From 90ea2e0c57e17ce44a00781c1f33e0680a928fda Mon Sep 17 00:00:00 2001
From: Cliff Hansen <cwhanse@sandia.gov>
Date: Fri, 21 Sep 2018 15:02:52 -0600
Subject: [PATCH 01/33] Initial commit for ephem_next_rise_set

---
 pvlib/solarposition.py           | 79 +++++++++++++++++++++++++++++++-
 pvlib/test/test_solarposition.py | 61 ++++++++++++++++--------
 2 files changed, 121 insertions(+), 19 deletions(-)

diff --git a/pvlib/solarposition.py b/pvlib/solarposition.py
index 7f3ed3f8fb..86a2fff5c3 100644
--- a/pvlib/solarposition.py
+++ b/pvlib/solarposition.py
@@ -438,6 +438,24 @@ def get_sun_rise_set_transit(time, latitude, longitude, how='numpy',
     return result
 
 
+def _ephem_convert_to_seconds_and_microseconds(date):
+    # utility from unreleased PyEphem 3.6.7.1
+    """Converts a PyEphem date into seconds"""
+    microseconds = int(round(24 * 60 * 60 * 1000000 * date))
+    seconds, microseconds = divmod(microseconds, 1000000)
+    seconds -= 2209032000  # difference between epoch 1900 and epoch 1970
+    return seconds, microseconds
+
+
+def _ephem_to_timezone(date, tzinfo):
+    # utility from unreleased PyEphem 3.6.7.1
+    """"Convert a PyEphem date into a timezone aware Python datetime representation."""
+    seconds, microseconds = _ephem_convert_to_seconds_and_microseconds(date)
+    date = dt.datetime.fromtimestamp(seconds, tzinfo)
+    date = date.replace(microsecond=microseconds)
+    return date
+
+
 def _ephem_setup(latitude, longitude, altitude, pressure, temperature):
     import ephem
     # initialize a PyEphem observer
@@ -453,6 +471,63 @@ def _ephem_setup(latitude, longitude, altitude, pressure, temperature):
     return obs, sun
 
 
+def ephem_next_rise_set(time, latitude, longitude, altitude=0,
+                        pressure=101325, temperature=12):
+    """
+    Calculate the next sunrise and sunset times using the PyEphem package.
+
+    Parameters
+    ----------
+    time : pandas.DatetimeIndex
+        Localized or UTC.
+    latitude : float
+        positive is north of 0
+    longitude : float
+        positive is east of 0
+    altitude : float, default 0
+        distance above sea level in meters.
+    pressure : int or float, optional, default 101325
+        air pressure in Pascals.
+    temperature : int or float, optional, default 12
+        air temperature in degrees C.
+
+    Returns
+    -------
+    pandas.DataFrame
+        index is the same as input time.index
+        columns are 'sunrise' and 'sunset', times are localized to the
+        timezone time.tz
+
+    See also
+    --------
+    pyephem
+    """
+
+    try:
+        import ephem
+    except ImportError:
+        raise ImportError('PyEphem must be installed')
+
+    # if localized, convert to UTC. otherwise, assume UTC.
+    try:
+        time_utc = time.tz_convert('UTC')
+    except TypeError:
+        time_utc = time
+
+    obs, sun = _ephem_setup(latitude, longitude, altitude,
+                            pressure, temperature)
+    # create lists of the next sunrise and sunset time localized to time.tz
+    next_sunrise = []
+    next_sunset = []
+    for thetime in time_utc:
+        obs.date = ephem.Date(thetime)
+        next_sunrise.append(_ephem_to_timezone(obs.next_rising(sun), time.tz))
+        next_sunset.append(_ephem_to_timezone(obs.next_setting(sun), time.tz))
+
+    return pd.DataFrame(index=time, data={'sunrise' : next_sunrise,
+                                          'sunset' : next_sunset})
+
+
 def pyephem(time, latitude, longitude, altitude=0, pressure=101325,
             temperature=12):
     """
@@ -463,9 +538,11 @@ def pyephem(time, latitude, longitude, altitude=0, pressure=101325,
     time : pandas.DatetimeIndex
         Localized or UTC.
     latitude : float
+        positive is north of 0
     longitude : float
+        positive is east of 0
     altitude : float, default 0
-        distance above sea level.
+        distance above sea level in meters.
     pressure : int or float, optional, default 101325
         air pressure in Pascals.
     temperature : int or float, optional, default 12
diff --git a/pvlib/test/test_solarposition.py b/pvlib/test/test_solarposition.py
index b99e5e7ff4..2ed387be9f 100644
--- a/pvlib/test/test_solarposition.py
+++ b/pvlib/test/test_solarposition.py
@@ -45,6 +45,21 @@ def expected_solpos_multi():
                          'apparent_elevation': [39.888378, 39.521740]},
                         index=[['2003-10-17T12:30:30Z', '2003-10-18T12:30:30Z']])
 
+@pytest.fixture()
+def expected_rise_set():
+    # for Golden, CO, from USNO website
+    times = pd.DatetimeIndex([datetime.datetime(2015, 1, 2),
+                              datetime.datetime(2015, 8, 2),]
+                             ).tz_localize('MST')
+    sunrise = pd.DatetimeIndex([datetime.datetime(2015, 1, 2, 7, 19, 2),
+                                datetime.datetime(2015, 8, 2, 5, 1, 26)
+                                ]).tz_localize('MST').tolist()
+    sunset = pd.DatetimeIndex([datetime.datetime(2015, 1, 2, 16, 49, 10),
+                               datetime.datetime(2015, 8, 2, 19, 11, 31)
+                               ]).tz_localize('MST').tolist()
+    return pd.DataFrame({'sunrise':sunrise, 'sunset':sunset}, index=times)
+
+
 # the physical tests are run at the same time as the NREL SPA test.
 # pyephem reproduces the NREL result to 2 decimal places.
 # this doesn't mean that one code is better than the other.
@@ -125,7 +140,7 @@ def test_spa_python_numba_physical_dst(expected_solpos):
 
 
 @needs_pandas_0_17
-def test_get_sun_rise_set_transit():
+def test_get_sun_rise_set_transit(expected_rise_set):
     south = Location(-35.0, 0.0, tz='UTC')
     times = pd.DatetimeIndex([datetime.datetime(1996, 7, 5, 0),
                               datetime.datetime(2004, 12, 4, 0)]
@@ -136,10 +151,11 @@ def test_get_sun_rise_set_transit():
     sunset = pd.DatetimeIndex([datetime.datetime(1996, 7, 5, 17, 1, 4),
                                datetime.datetime(2004, 12, 4, 19, 2, 2)]
                               ).tz_localize('UTC').tolist()
+    frame = pd.DataFrame({'sunrise':sunrise, 'sunset':sunset}, index=times)
+
     result = solarposition.get_sun_rise_set_transit(times, south.latitude,
                                                     south.longitude,
                                                     delta_t=64.0)
-    frame = pd.DataFrame({'sunrise':sunrise, 'sunset':sunset}, index=times)
     result_rounded = pd.DataFrame(index=result.index)
     # need to iterate because to_datetime does not accept 2D data
     # the rounding fails on pandas < 0.17
@@ -150,23 +166,11 @@ def test_get_sun_rise_set_transit():
     del result_rounded['transit']
     assert_frame_equal(frame, result_rounded)
 
-
-    # tests from USNO
-    # Golden
-    golden = Location(39.0, -105.0, tz='MST')
-    times = pd.DatetimeIndex([datetime.datetime(2015, 1, 2),
-                              datetime.datetime(2015, 8, 2),]
-                             ).tz_localize('MST')
-    sunrise = pd.DatetimeIndex([datetime.datetime(2015, 1, 2, 7, 19, 2),
-                                datetime.datetime(2015, 8, 2, 5, 1, 26)
-                                ]).tz_localize('MST').tolist()
-    sunset = pd.DatetimeIndex([datetime.datetime(2015, 1, 2, 16, 49, 10),
-                               datetime.datetime(2015, 8, 2, 19, 11, 31)
-                               ]).tz_localize('MST').tolist()
-    result = solarposition.get_sun_rise_set_transit(times, golden.latitude,
+    # test for Golden, CO compare to USNO
+    result = solarposition.get_sun_rise_set_transit(expected_rise_set.index,
+                                                    golden.latitude,
                                                     golden.longitude,
                                                     delta_t=64.0)
-    frame = pd.DataFrame({'sunrise':sunrise, 'sunset':sunset}, index=times)
     result_rounded = pd.DataFrame(index=result.index)
     # need to iterate because to_datetime does not accept 2D data
     # the rounding fails on pandas < 0.17
@@ -176,7 +180,25 @@ def test_get_sun_rise_set_transit():
             .tz_convert('MST'))
 
     del result_rounded['transit']
-    assert_frame_equal(frame, result_rounded)
+    assert_frame_equal(expected_rise_set, result_rounded)
+
+
+@requires_ephem
+def test_ephem_next_rise_set(expected_rise_set):
+    # test for Golden, CO compare to USNO
+    result = solarposition.ephem_next_rise_set(expected_rise_set.index,
+                                               golden.latitude,
+                                               golden.longitude,
+                                               golden.altitude,
+                                               pressure=101325,
+                                               temperature=12)
+    result_rounded = pd.DataFrame(index=result.index)
+    for col, data in result.iteritems():
+        result_rounded[col] = (pd.to_datetime(
+            np.floor(data.values.astype(np.int64) / 1e9)*1e9, utc=True)
+            .tz_convert('MST'))
+
+    assert_frame_equal(expected_rise_set, result_rounded)
 
 
 @requires_ephem
@@ -190,6 +212,7 @@ def test_pyephem_physical(expected_solpos):
     assert_frame_equal(expected_solpos.round(2),
                        ephem_data[expected_solpos.columns].round(2))
 
+
 @requires_ephem
 def test_pyephem_physical_dst(expected_solpos):
     times = pd.date_range(datetime.datetime(2003,10,17,13,30,30), periods=1,
@@ -201,6 +224,7 @@ def test_pyephem_physical_dst(expected_solpos):
     assert_frame_equal(expected_solpos.round(2),
                        ephem_data[expected_solpos.columns].round(2))
 
+
 @requires_ephem
 def test_calc_time():
     import pytz
@@ -227,6 +251,7 @@ def test_calc_time():
     assert_allclose((az.replace(second=0, microsecond=0) -
                           epoch_dt).total_seconds(), actual_timestamp)
 
+
 @requires_ephem
 def test_earthsun_distance():
     times = pd.date_range(datetime.datetime(2003,10,17,13,30,30),

From 0b9df182b9fc78521d446875cc9d887d8a1ab931 Mon Sep 17 00:00:00 2001
From: Cliff Hansen <cwhanse@sandia.gov>
Date: Fri, 21 Sep 2018 15:22:03 -0600
Subject: [PATCH 02/33] Stickler issues

---
 pvlib/solarposition.py           | 6 +++---
 pvlib/test/test_solarposition.py | 9 ++++++---
 2 files changed, 9 insertions(+), 6 deletions(-)

diff --git a/pvlib/solarposition.py b/pvlib/solarposition.py
index 86a2fff5c3..639495d17b 100644
--- a/pvlib/solarposition.py
+++ b/pvlib/solarposition.py
@@ -449,7 +449,7 @@ def _ephem_convert_to_seconds_and_microseconds(date):
 
 def _ephem_to_timezone(date, tzinfo):
     # utility from unreleased PyEphem 3.6.7.1
-    """"Convert a PyEphem date into a timezone aware Python datetime representation."""
+    """"Convert a PyEphem Date into a timezone aware python datetime"""
     seconds, microseconds = _ephem_convert_to_seconds_and_microseconds(date)
     date = dt.datetime.fromtimestamp(seconds, tzinfo)
     date = date.replace(microsecond=microseconds)
@@ -524,8 +524,8 @@ def ephem_next_rise_set(time, latitude, longitude, altitude=0,
         next_sunrise.append(_ephem_to_timezone(obs.next_rising(sun), time.tz))
         next_sunset.append(_ephem_to_timezone(obs.next_setting(sun), time.tz))
 
-    return pd.DataFrame(index=time, data={'sunrise' : next_sunrise,
-                                          'sunset' : next_sunset})
+    return pd.DataFrame(index=time, data={'sunrise': next_sunrise,
+                                          'sunset': next_sunset})
 
 
 def pyephem(time, latitude, longitude, altitude=0, pressure=101325,
diff --git a/pvlib/test/test_solarposition.py b/pvlib/test/test_solarposition.py
index 2ed387be9f..e8ed7e3d4d 100644
--- a/pvlib/test/test_solarposition.py
+++ b/pvlib/test/test_solarposition.py
@@ -29,6 +29,7 @@
 
 tol = 5
 
+
 @pytest.fixture()
 def expected_solpos():
     return pd.DataFrame({'elevation': 39.872046,
@@ -37,6 +38,7 @@ def expected_solpos():
                          'apparent_elevation': 39.888378},
                         index=['2003-10-17T12:30:30Z'])
 
+
 @pytest.fixture()
 def expected_solpos_multi():
     return pd.DataFrame({'elevation': [39.872046, 39.505196],
@@ -45,19 +47,20 @@ def expected_solpos_multi():
                          'apparent_elevation': [39.888378, 39.521740]},
                         index=[['2003-10-17T12:30:30Z', '2003-10-18T12:30:30Z']])
 
+
 @pytest.fixture()
 def expected_rise_set():
     # for Golden, CO, from USNO website
     times = pd.DatetimeIndex([datetime.datetime(2015, 1, 2),
-                              datetime.datetime(2015, 8, 2),]
-                             ).tz_localize('MST')
+                              datetime.datetime(2015, 8, 2),
+                              ]).tz_localize('MST')
     sunrise = pd.DatetimeIndex([datetime.datetime(2015, 1, 2, 7, 19, 2),
                                 datetime.datetime(2015, 8, 2, 5, 1, 26)
                                 ]).tz_localize('MST').tolist()
     sunset = pd.DatetimeIndex([datetime.datetime(2015, 1, 2, 16, 49, 10),
                                datetime.datetime(2015, 8, 2, 19, 11, 31)
                                ]).tz_localize('MST').tolist()
-    return pd.DataFrame({'sunrise':sunrise, 'sunset':sunset}, index=times)
+    return pd.DataFrame({'sunrise': sunrise, 'sunset': sunset}, index=times)
 
 
 # the physical tests are run at the same time as the NREL SPA test.

From 86cdfa73b5aee6df503225570bf5bd4505edebe0 Mon Sep 17 00:00:00 2001
From: Cliff Hansen <cwhanse@sandia.gov>
Date: Fri, 21 Sep 2018 15:49:49 -0600
Subject: [PATCH 03/33] Change test result and rounding to nearest minute

---
 pvlib/test/test_solarposition.py | 15 +++++++++------
 1 file changed, 9 insertions(+), 6 deletions(-)

diff --git a/pvlib/test/test_solarposition.py b/pvlib/test/test_solarposition.py
index e8ed7e3d4d..d4da6d0e19 100644
--- a/pvlib/test/test_solarposition.py
+++ b/pvlib/test/test_solarposition.py
@@ -54,11 +54,11 @@ def expected_rise_set():
     times = pd.DatetimeIndex([datetime.datetime(2015, 1, 2),
                               datetime.datetime(2015, 8, 2),
                               ]).tz_localize('MST')
-    sunrise = pd.DatetimeIndex([datetime.datetime(2015, 1, 2, 7, 19, 2),
-                                datetime.datetime(2015, 8, 2, 5, 1, 26)
+    sunrise = pd.DatetimeIndex([datetime.datetime(2015, 1, 2, 7, 22, 0),
+                                datetime.datetime(2015, 8, 2, 5, 1, 0)
                                 ]).tz_localize('MST').tolist()
-    sunset = pd.DatetimeIndex([datetime.datetime(2015, 1, 2, 16, 49, 10),
-                               datetime.datetime(2015, 8, 2, 19, 11, 31)
+    sunset = pd.DatetimeIndex([datetime.datetime(2015, 1, 2, 16, 48, 0),
+                               datetime.datetime(2015, 8, 2, 19, 13, 0)
                                ]).tz_localize('MST').tolist()
     return pd.DataFrame({'sunrise': sunrise, 'sunset': sunset}, index=times)
 
@@ -174,12 +174,14 @@ def test_get_sun_rise_set_transit(expected_rise_set):
                                                     golden.latitude,
                                                     golden.longitude,
                                                     delta_t=64.0)
+
+    # round to nearest minute
     result_rounded = pd.DataFrame(index=result.index)
     # need to iterate because to_datetime does not accept 2D data
     # the rounding fails on pandas < 0.17
     for col, data in result.iteritems():
         result_rounded[col] = (pd.to_datetime(
-            np.floor(data.values.astype(np.int64) / 1e9)*1e9, utc=True)
+            np.floor(data.values.astype(np.int64) / 60e9)*60e9, utc=True)
             .tz_convert('MST'))
 
     del result_rounded['transit']
@@ -195,10 +197,11 @@ def test_ephem_next_rise_set(expected_rise_set):
                                                golden.altitude,
                                                pressure=101325,
                                                temperature=12)
+    # round to nearest minute
     result_rounded = pd.DataFrame(index=result.index)
     for col, data in result.iteritems():
         result_rounded[col] = (pd.to_datetime(
-            np.floor(data.values.astype(np.int64) / 1e9)*1e9, utc=True)
+            np.floor(data.values.astype(np.int64) / 60e9)*60e9, utc=True)
             .tz_convert('MST'))
 
     assert_frame_equal(expected_rise_set, result_rounded)

From 06aef3f2da9b9651d0c645e449f4d991d82e899e Mon Sep 17 00:00:00 2001
From: Cliff Hansen <cwhanse@sandia.gov>
Date: Fri, 21 Sep 2018 16:15:14 -0600
Subject: [PATCH 04/33] Edit test condition, round not floor

---
 pvlib/test/test_solarposition.py | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/pvlib/test/test_solarposition.py b/pvlib/test/test_solarposition.py
index d4da6d0e19..23d9942f6c 100644
--- a/pvlib/test/test_solarposition.py
+++ b/pvlib/test/test_solarposition.py
@@ -164,7 +164,7 @@ def test_get_sun_rise_set_transit(expected_rise_set):
     # the rounding fails on pandas < 0.17
     for col, data in result.iteritems():
         result_rounded[col] = pd.to_datetime(
-            np.floor(data.values.astype(np.int64) / 1e9)*1e9, utc=True)
+            np.floor(data.values.astype(np.int64) / 1e9) * 1e9, utc=True)
 
     del result_rounded['transit']
     assert_frame_equal(frame, result_rounded)
@@ -181,7 +181,7 @@ def test_get_sun_rise_set_transit(expected_rise_set):
     # the rounding fails on pandas < 0.17
     for col, data in result.iteritems():
         result_rounded[col] = (pd.to_datetime(
-            np.floor(data.values.astype(np.int64) / 60e9)*60e9, utc=True)
+            np.round(data.values.astype(np.int64)), utc=True)
             .tz_convert('MST'))
 
     del result_rounded['transit']
@@ -189,7 +189,7 @@ def test_get_sun_rise_set_transit(expected_rise_set):
 
 
 @requires_ephem
-def test_ephem_next_rise_set(expected_rise_set):
+def test_next_rise_set_ephem(expected_rise_set):
     # test for Golden, CO compare to USNO
     result = solarposition.ephem_next_rise_set(expected_rise_set.index,
                                                golden.latitude,
@@ -201,7 +201,7 @@ def test_ephem_next_rise_set(expected_rise_set):
     result_rounded = pd.DataFrame(index=result.index)
     for col, data in result.iteritems():
         result_rounded[col] = (pd.to_datetime(
-            np.floor(data.values.astype(np.int64) / 60e9)*60e9, utc=True)
+            np.round(data.values.astype(np.int64)), utc=True)
             .tz_convert('MST'))
 
     assert_frame_equal(expected_rise_set, result_rounded)

From a22d8466e51ffbaba068156dee0ac81600fa39c6 Mon Sep 17 00:00:00 2001
From: Cliff Hansen <cwhanse@sandia.gov>
Date: Sat, 22 Sep 2018 11:03:48 -0600
Subject: [PATCH 05/33] Change explicit rounding to pandas .round('min')

---
 pvlib/test/test_solarposition.py | 7 ++-----
 1 file changed, 2 insertions(+), 5 deletions(-)

diff --git a/pvlib/test/test_solarposition.py b/pvlib/test/test_solarposition.py
index 23d9942f6c..ad3b7ccab6 100644
--- a/pvlib/test/test_solarposition.py
+++ b/pvlib/test/test_solarposition.py
@@ -163,8 +163,7 @@ def test_get_sun_rise_set_transit(expected_rise_set):
     # need to iterate because to_datetime does not accept 2D data
     # the rounding fails on pandas < 0.17
     for col, data in result.iteritems():
-        result_rounded[col] = pd.to_datetime(
-            np.floor(data.values.astype(np.int64) / 1e9) * 1e9, utc=True)
+        result_rounded[col] = data.dt.round('min')
 
     del result_rounded['transit']
     assert_frame_equal(frame, result_rounded)
@@ -180,9 +179,7 @@ def test_get_sun_rise_set_transit(expected_rise_set):
     # need to iterate because to_datetime does not accept 2D data
     # the rounding fails on pandas < 0.17
     for col, data in result.iteritems():
-        result_rounded[col] = (pd.to_datetime(
-            np.round(data.values.astype(np.int64)), utc=True)
-            .tz_convert('MST'))
+        result_rounded[col] = data.dt.round('min').tz_convert('MST')
 
     del result_rounded['transit']
     assert_frame_equal(expected_rise_set, result_rounded)

From 719009d3be30dc7af2615eb3cd63bcda4e7c0ff9 Mon Sep 17 00:00:00 2001
From: Cliff Hansen <cwhanse@sandia.gov>
Date: Sat, 22 Sep 2018 15:53:09 -0600
Subject: [PATCH 06/33] More test fixes

---
 pvlib/test/test_solarposition.py | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/pvlib/test/test_solarposition.py b/pvlib/test/test_solarposition.py
index ad3b7ccab6..cf310db52b 100644
--- a/pvlib/test/test_solarposition.py
+++ b/pvlib/test/test_solarposition.py
@@ -163,7 +163,7 @@ def test_get_sun_rise_set_transit(expected_rise_set):
     # need to iterate because to_datetime does not accept 2D data
     # the rounding fails on pandas < 0.17
     for col, data in result.iteritems():
-        result_rounded[col] = data.dt.round('min')
+        result_rounded[col] = data.dt.round('sec')
 
     del result_rounded['transit']
     assert_frame_equal(frame, result_rounded)
@@ -197,9 +197,7 @@ def test_next_rise_set_ephem(expected_rise_set):
     # round to nearest minute
     result_rounded = pd.DataFrame(index=result.index)
     for col, data in result.iteritems():
-        result_rounded[col] = (pd.to_datetime(
-            np.round(data.values.astype(np.int64)), utc=True)
-            .tz_convert('MST'))
+        result_rounded[col] = data.dt.round('min').tz_convert('MST')
 
     assert_frame_equal(expected_rise_set, result_rounded)
 

From aa4f1d62e3855fbe7d88230b72c35a8c34c90353 Mon Sep 17 00:00:00 2001
From: Cliff Hansen <cwhanse@sandia.gov>
Date: Sat, 22 Sep 2018 16:08:25 -0600
Subject: [PATCH 07/33] Fix sec keyword

---
 pvlib/test/test_solarposition.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/pvlib/test/test_solarposition.py b/pvlib/test/test_solarposition.py
index cf310db52b..0de72e98b4 100644
--- a/pvlib/test/test_solarposition.py
+++ b/pvlib/test/test_solarposition.py
@@ -163,7 +163,7 @@ def test_get_sun_rise_set_transit(expected_rise_set):
     # need to iterate because to_datetime does not accept 2D data
     # the rounding fails on pandas < 0.17
     for col, data in result.iteritems():
-        result_rounded[col] = data.dt.round('sec')
+        result_rounded[col] = data.dt.round('1s')
 
     del result_rounded['transit']
     assert_frame_equal(frame, result_rounded)

From c08d213add553a066302a5bcb246f9fac85dd23a Mon Sep 17 00:00:00 2001
From: Cliff Hansen <cwhanse@sandia.gov>
Date: Sat, 22 Sep 2018 19:55:17 -0600
Subject: [PATCH 08/33] Add test for transit

---
 pvlib/test/test_solarposition.py | 13 ++++++++-----
 1 file changed, 8 insertions(+), 5 deletions(-)

diff --git a/pvlib/test/test_solarposition.py b/pvlib/test/test_solarposition.py
index 0de72e98b4..71f6e82ea2 100644
--- a/pvlib/test/test_solarposition.py
+++ b/pvlib/test/test_solarposition.py
@@ -55,12 +55,17 @@ def expected_rise_set():
                               datetime.datetime(2015, 8, 2),
                               ]).tz_localize('MST')
     sunrise = pd.DatetimeIndex([datetime.datetime(2015, 1, 2, 7, 22, 0),
-                                datetime.datetime(2015, 8, 2, 5, 1, 0)
+                                datetime.datetime(2015, 8, 2, 5, 0, 0)
                                 ]).tz_localize('MST').tolist()
     sunset = pd.DatetimeIndex([datetime.datetime(2015, 1, 2, 16, 48, 0),
                                datetime.datetime(2015, 8, 2, 19, 13, 0)
                                ]).tz_localize('MST').tolist()
-    return pd.DataFrame({'sunrise': sunrise, 'sunset': sunset}, index=times)
+    transit = pd.DatetimeIndex([datetime.datetime(2015, 1, 2, 12, 5, 0),
+                                datetime.datetime(2015, 8, 2, 12, 7, 0)
+                               ]).tz_localize('MST').tolist()
+    return pd.DataFrame({'sunrise': sunrise,
+                         'sunset': sunset,
+                         'transit': transit}, index=times)
 
 
 # the physical tests are run at the same time as the NREL SPA test.
@@ -177,11 +182,9 @@ def test_get_sun_rise_set_transit(expected_rise_set):
     # round to nearest minute
     result_rounded = pd.DataFrame(index=result.index)
     # need to iterate because to_datetime does not accept 2D data
-    # the rounding fails on pandas < 0.17
     for col, data in result.iteritems():
         result_rounded[col] = data.dt.round('min').tz_convert('MST')
 
-    del result_rounded['transit']
     assert_frame_equal(expected_rise_set, result_rounded)
 
 
@@ -198,7 +201,7 @@ def test_next_rise_set_ephem(expected_rise_set):
     result_rounded = pd.DataFrame(index=result.index)
     for col, data in result.iteritems():
         result_rounded[col] = data.dt.round('min').tz_convert('MST')
-
+    del expected_rise_set('transit')
     assert_frame_equal(expected_rise_set, result_rounded)
 
 

From f192547df88b173f281ba65760d751bcd27618ef Mon Sep 17 00:00:00 2001
From: Cliff Hansen <cwhanse@sandia.gov>
Date: Sat, 22 Sep 2018 20:21:40 -0600
Subject: [PATCH 09/33] Fix del statement

---
 pvlib/test/test_solarposition.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/pvlib/test/test_solarposition.py b/pvlib/test/test_solarposition.py
index 71f6e82ea2..eb0053e4aa 100644
--- a/pvlib/test/test_solarposition.py
+++ b/pvlib/test/test_solarposition.py
@@ -201,7 +201,7 @@ def test_next_rise_set_ephem(expected_rise_set):
     result_rounded = pd.DataFrame(index=result.index)
     for col, data in result.iteritems():
         result_rounded[col] = data.dt.round('min').tz_convert('MST')
-    del expected_rise_set('transit')
+    del expected_rise_set['transit']
     assert_frame_equal(expected_rise_set, result_rounded)
 
 

From 377658b7d41b16cb548845ab9d640b6b9e122ebd Mon Sep 17 00:00:00 2001
From: Cliff Hansen <cwhanse@sandia.gov>
Date: Sat, 22 Sep 2018 20:40:44 -0600
Subject: [PATCH 10/33] Fix column order

---
 pvlib/test/test_solarposition.py | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/pvlib/test/test_solarposition.py b/pvlib/test/test_solarposition.py
index eb0053e4aa..7adf309502 100644
--- a/pvlib/test/test_solarposition.py
+++ b/pvlib/test/test_solarposition.py
@@ -63,9 +63,10 @@ def expected_rise_set():
     transit = pd.DatetimeIndex([datetime.datetime(2015, 1, 2, 12, 5, 0),
                                 datetime.datetime(2015, 8, 2, 12, 7, 0)
                                ]).tz_localize('MST').tolist()
-    return pd.DataFrame({'sunrise': sunrise,
+    return pd.DataFrame({'transit': transit,
+                         'sunrise': sunrise,
                          'sunset': sunset,
-                         'transit': transit}, index=times)
+                         }, index=times)
 
 
 # the physical tests are run at the same time as the NREL SPA test.

From f338781693788b6df1b5f0e5628cbefbf898c739 Mon Sep 17 00:00:00 2001
From: Cliff Hansen <cwhanse@sandia.gov>
Date: Sat, 22 Sep 2018 22:17:07 -0600
Subject: [PATCH 11/33] Change reference solution to NREL SPA website

---
 pvlib/test/test_solarposition.py | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/pvlib/test/test_solarposition.py b/pvlib/test/test_solarposition.py
index 7adf309502..50e17a1eca 100644
--- a/pvlib/test/test_solarposition.py
+++ b/pvlib/test/test_solarposition.py
@@ -50,7 +50,7 @@ def expected_solpos_multi():
 
 @pytest.fixture()
 def expected_rise_set():
-    # for Golden, CO, from USNO website
+    # for Golden, CO, from NREL SPA website
     times = pd.DatetimeIndex([datetime.datetime(2015, 1, 2),
                               datetime.datetime(2015, 8, 2),
                               ]).tz_localize('MST')
@@ -58,7 +58,7 @@ def expected_rise_set():
                                 datetime.datetime(2015, 8, 2, 5, 0, 0)
                                 ]).tz_localize('MST').tolist()
     sunset = pd.DatetimeIndex([datetime.datetime(2015, 1, 2, 16, 48, 0),
-                               datetime.datetime(2015, 8, 2, 19, 13, 0)
+                               datetime.datetime(2015, 8, 2, 19, 14, 0)
                                ]).tz_localize('MST').tolist()
     transit = pd.DatetimeIndex([datetime.datetime(2015, 1, 2, 12, 5, 0),
                                 datetime.datetime(2015, 8, 2, 12, 7, 0)
@@ -164,7 +164,7 @@ def test_get_sun_rise_set_transit(expected_rise_set):
 
     result = solarposition.get_sun_rise_set_transit(times, south.latitude,
                                                     south.longitude,
-                                                    delta_t=64.0)
+                                                    delta_t=65.0)
     result_rounded = pd.DataFrame(index=result.index)
     # need to iterate because to_datetime does not accept 2D data
     # the rounding fails on pandas < 0.17
@@ -174,11 +174,11 @@ def test_get_sun_rise_set_transit(expected_rise_set):
     del result_rounded['transit']
     assert_frame_equal(frame, result_rounded)
 
-    # test for Golden, CO compare to USNO
+    # test for Golden, CO compare to NREL SPA
     result = solarposition.get_sun_rise_set_transit(expected_rise_set.index,
                                                     golden.latitude,
                                                     golden.longitude,
-                                                    delta_t=64.0)
+                                                    delta_t=65.0)
 
     # round to nearest minute
     result_rounded = pd.DataFrame(index=result.index)
@@ -191,7 +191,7 @@ def test_get_sun_rise_set_transit(expected_rise_set):
 
 @requires_ephem
 def test_next_rise_set_ephem(expected_rise_set):
-    # test for Golden, CO compare to USNO
+    # test for Golden, CO compare to NREL SPA
     result = solarposition.ephem_next_rise_set(expected_rise_set.index,
                                                golden.latitude,
                                                golden.longitude,

From a3bedc0daacffcedb7920bda4686bf7ff5781d61 Mon Sep 17 00:00:00 2001
From: Cliff Hansen <cwhanse@sandia.gov>
Date: Sat, 22 Sep 2018 22:33:00 -0600
Subject: [PATCH 12/33] Adjust pressure and temp for pyephem

---
 pvlib/test/test_solarposition.py | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/pvlib/test/test_solarposition.py b/pvlib/test/test_solarposition.py
index 50e17a1eca..7d3334457f 100644
--- a/pvlib/test/test_solarposition.py
+++ b/pvlib/test/test_solarposition.py
@@ -62,7 +62,7 @@ def expected_rise_set():
                                ]).tz_localize('MST').tolist()
     transit = pd.DatetimeIndex([datetime.datetime(2015, 1, 2, 12, 5, 0),
                                 datetime.datetime(2015, 8, 2, 12, 7, 0)
-                               ]).tz_localize('MST').tolist()
+                                ]).tz_localize('MST').tolist()
     return pd.DataFrame({'transit': transit,
                          'sunrise': sunrise,
                          'sunset': sunset,
@@ -158,7 +158,7 @@ def test_get_sun_rise_set_transit(expected_rise_set):
                                 datetime.datetime(2004, 12, 4, 4, 38, 57)]
                                ).tz_localize('UTC').tolist()
     sunset = pd.DatetimeIndex([datetime.datetime(1996, 7, 5, 17, 1, 4),
-                               datetime.datetime(2004, 12, 4, 19, 2, 2)]
+                               datetime.datetime(2004, 12, 4, 19, 2, 3)]
                               ).tz_localize('UTC').tolist()
     frame = pd.DataFrame({'sunrise':sunrise, 'sunset':sunset}, index=times)
 
@@ -196,8 +196,8 @@ def test_next_rise_set_ephem(expected_rise_set):
                                                golden.latitude,
                                                golden.longitude,
                                                golden.altitude,
-                                               pressure=101325,
-                                               temperature=12)
+                                               pressure=82000,
+                                               temperature=11)
     # round to nearest minute
     result_rounded = pd.DataFrame(index=result.index)
     for col, data in result.iteritems():

From 17564dd5f0f95dbcb77600f1cdb33db787fad7a8 Mon Sep 17 00:00:00 2001
From: Cliff Hansen <cwhanse@sandia.gov>
Date: Sun, 23 Sep 2018 08:18:13 -0600
Subject: [PATCH 13/33] Add horizon kwarg for pyephem

---
 pvlib/solarposition.py           | 14 ++++++++++----
 pvlib/test/test_solarposition.py | 15 ++++++++-------
 2 files changed, 18 insertions(+), 11 deletions(-)

diff --git a/pvlib/solarposition.py b/pvlib/solarposition.py
index 639495d17b..bd2a5cc126 100644
--- a/pvlib/solarposition.py
+++ b/pvlib/solarposition.py
@@ -456,7 +456,8 @@ def _ephem_to_timezone(date, tzinfo):
     return date
 
 
-def _ephem_setup(latitude, longitude, altitude, pressure, temperature):
+def _ephem_setup(latitude, longitude, altitude, pressure, temperature,
+                 horizon):
     import ephem
     # initialize a PyEphem observer
     obs = ephem.Observer()
@@ -465,14 +466,15 @@ def _ephem_setup(latitude, longitude, altitude, pressure, temperature):
     obs.elevation = altitude
     obs.pressure = pressure / 100.  # convert to mBar
     obs.temp = temperature
+    obs.horizon = horizon
 
     # the PyEphem sun
     sun = ephem.Sun()
     return obs, sun
 
 
-def ephem_next_rise_set(time, latitude, longitude, altitude=0,
-                        pressure=101325, temperature=12):
+def next_rise_set_ephem(time, latitude, longitude, altitude=0,
+                        pressure=101325, temperature=12, horizon='0:00'):
     """
     Calculate the next sunrise and sunset times using the PyEphem package.
 
@@ -490,6 +492,10 @@ def ephem_next_rise_set(time, latitude, longitude, altitude=0,
         air pressure in Pascals.
     temperature : int or float, optional, default 12
         air temperature in degrees C.
+    horizon : string, format +/-X:YY
+        arc degrees:arc minutes from geometrical horizon for sunrise and
+        sunset, e.g., horizon='-0:34' when the sun's upper edge crosses the
+        geometrical horizon
 
     Returns
     -------
@@ -515,7 +521,7 @@ def ephem_next_rise_set(time, latitude, longitude, altitude=0,
         time_utc = time
 
     obs, sun = _ephem_setup(latitude, longitude, altitude,
-                            pressure, temperature)
+                            pressure, temperature, horizon)
     # create lists of the next sunrise and sunset time localized to time.tz
     next_sunrise = []
     next_sunset = []
diff --git a/pvlib/test/test_solarposition.py b/pvlib/test/test_solarposition.py
index 7d3334457f..6a7bf616cc 100644
--- a/pvlib/test/test_solarposition.py
+++ b/pvlib/test/test_solarposition.py
@@ -50,7 +50,7 @@ def expected_solpos_multi():
 
 @pytest.fixture()
 def expected_rise_set():
-    # for Golden, CO, from NREL SPA website
+    # for Golden, CO, from NREL SPA and USNO websites
     times = pd.DatetimeIndex([datetime.datetime(2015, 1, 2),
                               datetime.datetime(2015, 8, 2),
                               ]).tz_localize('MST')
@@ -58,7 +58,7 @@ def expected_rise_set():
                                 datetime.datetime(2015, 8, 2, 5, 0, 0)
                                 ]).tz_localize('MST').tolist()
     sunset = pd.DatetimeIndex([datetime.datetime(2015, 1, 2, 16, 48, 0),
-                               datetime.datetime(2015, 8, 2, 19, 14, 0)
+                               datetime.datetime(2015, 8, 2, 19, 13, 0)
                                ]).tz_localize('MST').tolist()
     transit = pd.DatetimeIndex([datetime.datetime(2015, 1, 2, 12, 5, 0),
                                 datetime.datetime(2015, 8, 2, 12, 7, 0)
@@ -160,7 +160,7 @@ def test_get_sun_rise_set_transit(expected_rise_set):
     sunset = pd.DatetimeIndex([datetime.datetime(1996, 7, 5, 17, 1, 4),
                                datetime.datetime(2004, 12, 4, 19, 2, 3)]
                               ).tz_localize('UTC').tolist()
-    frame = pd.DataFrame({'sunrise':sunrise, 'sunset':sunset}, index=times)
+    frame = pd.DataFrame({'sunrise': sunrise, 'sunset': sunset}, index=times)
 
     result = solarposition.get_sun_rise_set_transit(times, south.latitude,
                                                     south.longitude,
@@ -191,13 +191,14 @@ def test_get_sun_rise_set_transit(expected_rise_set):
 
 @requires_ephem
 def test_next_rise_set_ephem(expected_rise_set):
-    # test for Golden, CO compare to NREL SPA
-    result = solarposition.ephem_next_rise_set(expected_rise_set.index,
+    # test for Golden, CO compare to USNO
+    result = solarposition.next_rise_set_ephem(expected_rise_set.index,
                                                golden.latitude,
                                                golden.longitude,
                                                golden.altitude,
-                                               pressure=82000,
-                                               temperature=11)
+                                               pressure=0,
+                                               temperature=11,
+                                               horizon='-0:34')
     # round to nearest minute
     result_rounded = pd.DataFrame(index=result.index)
     for col, data in result.iteritems():

From c29ed0652ee3b0b2bd42717138089bef853a9592 Mon Sep 17 00:00:00 2001
From: Cliff Hansen <cwhanse@sandia.gov>
Date: Sun, 23 Sep 2018 12:40:59 -0600
Subject: [PATCH 14/33] Separate rise, set test for spa and pyephem

---
 pvlib/test/test_solarposition.py | 43 +++++++++++++++++++++++---------
 1 file changed, 31 insertions(+), 12 deletions(-)

diff --git a/pvlib/test/test_solarposition.py b/pvlib/test/test_solarposition.py
index 6a7bf616cc..96928bec2b 100644
--- a/pvlib/test/test_solarposition.py
+++ b/pvlib/test/test_solarposition.py
@@ -49,8 +49,29 @@ def expected_solpos_multi():
 
 
 @pytest.fixture()
-def expected_rise_set():
-    # for Golden, CO, from NREL SPA and USNO websites
+def expected_rise_set_spa():
+    # for Golden, CO, from NREL SPA website
+    times = pd.DatetimeIndex([datetime.datetime(2015, 1, 2),
+                              datetime.datetime(2015, 8, 2),
+                              ]).tz_localize('MST')
+    sunrise = pd.DatetimeIndex([datetime.datetime(2015, 1, 2, 7, 21, 55),
+                                datetime.datetime(2015, 8, 2, 5, 0, 27)
+                                ]).tz_localize('MST').tolist()
+    sunset = pd.DatetimeIndex([datetime.datetime(2015, 1, 2, 16, 47, 43),
+                               datetime.datetime(2015, 8, 2, 19, 12, 15)
+                               ]).tz_localize('MST').tolist()
+    transit = pd.DatetimeIndex([datetime.datetime(2015, 1, 2, 12, 4, 45),
+                                datetime.datetime(2015, 8, 2, 12, 6, 58)
+                                ]).tz_localize('MST').tolist()
+    return pd.DataFrame({'transit': transit,
+                         'sunrise': sunrise,
+                         'sunset': sunset,
+                         }, index=times)
+
+
+@pytest.fixture()
+def expected_rise_set_ephem():
+    # for Golden, CO, from USNO websites
     times = pd.DatetimeIndex([datetime.datetime(2015, 1, 2),
                               datetime.datetime(2015, 8, 2),
                               ]).tz_localize('MST')
@@ -67,8 +88,6 @@ def expected_rise_set():
                          'sunrise': sunrise,
                          'sunset': sunset,
                          }, index=times)
-
-
 # the physical tests are run at the same time as the NREL SPA test.
 # pyephem reproduces the NREL result to 2 decimal places.
 # this doesn't mean that one code is better than the other.
@@ -149,7 +168,7 @@ def test_spa_python_numba_physical_dst(expected_solpos):
 
 
 @needs_pandas_0_17
-def test_get_sun_rise_set_transit(expected_rise_set):
+def test_get_sun_rise_set_transit(expected_rise_set_spa):
     south = Location(-35.0, 0.0, tz='UTC')
     times = pd.DatetimeIndex([datetime.datetime(1996, 7, 5, 0),
                               datetime.datetime(2004, 12, 4, 0)]
@@ -175,7 +194,7 @@ def test_get_sun_rise_set_transit(expected_rise_set):
     assert_frame_equal(frame, result_rounded)
 
     # test for Golden, CO compare to NREL SPA
-    result = solarposition.get_sun_rise_set_transit(expected_rise_set.index,
+    result = solarposition.get_sun_rise_set_transit(expected_rise_set_spa.index,
                                                     golden.latitude,
                                                     golden.longitude,
                                                     delta_t=65.0)
@@ -184,15 +203,15 @@ def test_get_sun_rise_set_transit(expected_rise_set):
     result_rounded = pd.DataFrame(index=result.index)
     # need to iterate because to_datetime does not accept 2D data
     for col, data in result.iteritems():
-        result_rounded[col] = data.dt.round('min').tz_convert('MST')
+        result_rounded[col] = data.dt.round('s').tz_convert('MST')
 
-    assert_frame_equal(expected_rise_set, result_rounded)
+    assert_frame_equal(expected_rise_set_spa, result_rounded)
 
 
 @requires_ephem
-def test_next_rise_set_ephem(expected_rise_set):
+def test_next_rise_set_ephem(expected_rise_set_ephem):
     # test for Golden, CO compare to USNO
-    result = solarposition.next_rise_set_ephem(expected_rise_set.index,
+    result = solarposition.next_rise_set_ephem(expected_rise_set_ephem.index,
                                                golden.latitude,
                                                golden.longitude,
                                                golden.altitude,
@@ -203,8 +222,8 @@ def test_next_rise_set_ephem(expected_rise_set):
     result_rounded = pd.DataFrame(index=result.index)
     for col, data in result.iteritems():
         result_rounded[col] = data.dt.round('min').tz_convert('MST')
-    del expected_rise_set['transit']
-    assert_frame_equal(expected_rise_set, result_rounded)
+    del expected_rise_set_ephem['transit']
+    assert_frame_equal(expected_rise_set_ephem, result_rounded)
 
 
 @requires_ephem

From a3d143d4cd35e00b8d6baf6b6526c29362e119e5 Mon Sep 17 00:00:00 2001
From: Cliff Hansen <cwhanse@sandia.gov>
Date: Sun, 23 Sep 2018 14:11:53 -0600
Subject: [PATCH 15/33] Add horizon kwarg to pyephem, fix test condition for
 spa

---
 pvlib/solarposition.py           | 8 ++++++--
 pvlib/test/test_solarposition.py | 2 +-
 2 files changed, 7 insertions(+), 3 deletions(-)

diff --git a/pvlib/solarposition.py b/pvlib/solarposition.py
index bd2a5cc126..1c297d41fb 100644
--- a/pvlib/solarposition.py
+++ b/pvlib/solarposition.py
@@ -535,7 +535,7 @@ def next_rise_set_ephem(time, latitude, longitude, altitude=0,
 
 
 def pyephem(time, latitude, longitude, altitude=0, pressure=101325,
-            temperature=12):
+            temperature=12, horizon='+0:00'):
     """
     Calculate the solar position using the PyEphem package.
 
@@ -553,6 +553,10 @@ def pyephem(time, latitude, longitude, altitude=0, pressure=101325,
         air pressure in Pascals.
     temperature : int or float, optional, default 12
         air temperature in degrees C.
+    horizon : string, optional, default '+0:00'
+        arc degrees:arc minutes from geometrical horizon for sunrise and
+        sunset, e.g., horizon='-0:34' when the sun's upper edge crosses the
+        geometrical horizon
 
     Returns
     -------
@@ -582,7 +586,7 @@ def pyephem(time, latitude, longitude, altitude=0, pressure=101325,
     sun_coords = pd.DataFrame(index=time)
 
     obs, sun = _ephem_setup(latitude, longitude, altitude,
-                            pressure, temperature)
+                            pressure, temperature, horizon)
 
     # make and fill lists of the sun's altitude and azimuth
     # this is the pressure and temperature corrected apparent alt/az.
diff --git a/pvlib/test/test_solarposition.py b/pvlib/test/test_solarposition.py
index 96928bec2b..ef707fb7c6 100644
--- a/pvlib/test/test_solarposition.py
+++ b/pvlib/test/test_solarposition.py
@@ -58,7 +58,7 @@ def expected_rise_set_spa():
                                 datetime.datetime(2015, 8, 2, 5, 0, 27)
                                 ]).tz_localize('MST').tolist()
     sunset = pd.DatetimeIndex([datetime.datetime(2015, 1, 2, 16, 47, 43),
-                               datetime.datetime(2015, 8, 2, 19, 12, 15)
+                               datetime.datetime(2015, 8, 2, 19, 13, 58)
                                ]).tz_localize('MST').tolist()
     transit = pd.DatetimeIndex([datetime.datetime(2015, 1, 2, 12, 4, 45),
                                 datetime.datetime(2015, 8, 2, 12, 6, 58)

From 99a75a0992081417f7a6c32c73696a46385a631e Mon Sep 17 00:00:00 2001
From: Cliff Hansen <cwhanse@sandia.gov>
Date: Sun, 23 Sep 2018 14:52:11 -0600
Subject: [PATCH 16/33] Add horizon kwarg to calc_time

---
 pvlib/solarposition.py | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/pvlib/solarposition.py b/pvlib/solarposition.py
index 1c297d41fb..2608e9f241 100644
--- a/pvlib/solarposition.py
+++ b/pvlib/solarposition.py
@@ -798,7 +798,8 @@ def ephemeris(time, latitude, longitude, pressure=101325, temperature=12):
 
 
 def calc_time(lower_bound, upper_bound, latitude, longitude, attribute, value,
-              altitude=0, pressure=101325, temperature=12, xtol=1.0e-12):
+              altitude=0, pressure=101325, temperature=12, horizon='+0:00',
+              xtol=1.0e-12):
     """
     Calculate the time between lower_bound and upper_bound
     where the attribute is equal to value. Uses PyEphem for
@@ -823,6 +824,10 @@ def calc_time(lower_bound, upper_bound, latitude, longitude, attribute, value,
         atmospheric correction.
     temperature : int or float, optional, default 12
         Air temperature in degrees C.
+    horizon : string, optional, default '+0:00'
+        arc degrees:arc minutes from geometrical horizon for sunrise and
+        sunset, e.g., horizon='-0:34' when the sun's upper edge crosses the
+        geometrical horizon
     xtol : float, optional, default 1.0e-12
         The allowed error in the result from value
 
@@ -845,7 +850,7 @@ def calc_time(lower_bound, upper_bound, latitude, longitude, attribute, value,
         raise ImportError('The calc_time function requires scipy')
 
     obs, sun = _ephem_setup(latitude, longitude, altitude,
-                            pressure, temperature)
+                            pressure, temperature, horizon)
 
     def compute_attr(thetime, target, attr):
         obs.date = thetime

From 95187d523e3aa6eb8c42ffd869ba87c499ac1a72 Mon Sep 17 00:00:00 2001
From: Cliff Hansen <cwhanse@sandia.gov>
Date: Mon, 24 Sep 2018 10:20:20 -0600
Subject: [PATCH 17/33] Extend tests for next_rise_set_ephem

---
 pvlib/test/test_solarposition.py | 64 ++++++++++++++++++++++++++++++--
 1 file changed, 60 insertions(+), 4 deletions(-)

diff --git a/pvlib/test/test_solarposition.py b/pvlib/test/test_solarposition.py
index ef707fb7c6..be8ba3a0d1 100644
--- a/pvlib/test/test_solarposition.py
+++ b/pvlib/test/test_solarposition.py
@@ -65,29 +65,34 @@ def expected_rise_set_spa():
                                 ]).tz_localize('MST').tolist()
     return pd.DataFrame({'transit': transit,
                          'sunrise': sunrise,
-                         'sunset': sunset,
-                         }, index=times)
+                         'sunset': sunset},
+                        index=times,
+                        dtype='datetime64[ns]')
 
 
 @pytest.fixture()
 def expected_rise_set_ephem():
     # for Golden, CO, from USNO websites
     times = pd.DatetimeIndex([datetime.datetime(2015, 1, 2),
+                              datetime.datetime(2015, 1, 3),
                               datetime.datetime(2015, 8, 2),
                               ]).tz_localize('MST')
     sunrise = pd.DatetimeIndex([datetime.datetime(2015, 1, 2, 7, 22, 0),
+                                datetime.datetime(2015, 1, 3, 7, 22, 0),
                                 datetime.datetime(2015, 8, 2, 5, 0, 0)
                                 ]).tz_localize('MST').tolist()
     sunset = pd.DatetimeIndex([datetime.datetime(2015, 1, 2, 16, 48, 0),
+                               datetime.datetime(2015, 1, 3, 16, 49, 0),
                                datetime.datetime(2015, 8, 2, 19, 13, 0)
                                ]).tz_localize('MST').tolist()
     transit = pd.DatetimeIndex([datetime.datetime(2015, 1, 2, 12, 5, 0),
+                                datetime.datetime(2015, 1, 3, 12, 5, 0),
                                 datetime.datetime(2015, 8, 2, 12, 7, 0)
                                 ]).tz_localize('MST').tolist()
     return pd.DataFrame({'transit': transit,
                          'sunrise': sunrise,
-                         'sunset': sunset,
-                         }, index=times)
+                         'sunset': sunset},
+                        index=times)
 # the physical tests are run at the same time as the NREL SPA test.
 # pyephem reproduces the NREL result to 2 decimal places.
 # this doesn't mean that one code is better than the other.
@@ -225,6 +230,57 @@ def test_next_rise_set_ephem(expected_rise_set_ephem):
     del expected_rise_set_ephem['transit']
     assert_frame_equal(expected_rise_set_ephem, result_rounded)
 
+    # test with times
+    times = pd.DatetimeIndex([datetime.datetime(2015, 1, 2, 3, 0, 0),
+                              datetime.datetime(2015, 1, 2, 10, 15, 0),
+                              datetime.datetime(2015, 1, 2, 15, 3, 0),
+                              datetime.datetime(2015, 1, 2, 21, 6, 7)
+                              ]).tz_localize('MST')
+    expected = pd.DataFrame(index=times,
+                            columns=['sunrise', 'sunset'],
+                            dtype='datetime64[ns]')
+    expected['sunrise'] = pd.Series(index=times, data = \
+       [expected_rise_set_ephem.loc[datetime.datetime(2015, 1, 2), 'sunrise'],
+        expected_rise_set_ephem.loc[datetime.datetime(2015, 1, 3), 'sunrise'],
+        expected_rise_set_ephem.loc[datetime.datetime(2015, 1, 3), 'sunrise'],
+        expected_rise_set_ephem.loc[datetime.datetime(2015, 1, 3), 'sunrise']])
+    expected['sunset'] = pd.Series(index=times, data = \
+       [expected_rise_set_ephem.loc[datetime.datetime(2015, 1, 2), 'sunset'],
+        expected_rise_set_ephem.loc[datetime.datetime(2015, 1, 2), 'sunset'],
+        expected_rise_set_ephem.loc[datetime.datetime(2015, 1, 2), 'sunset'],
+        expected_rise_set_ephem.loc[datetime.datetime(2015, 1, 3), 'sunset']])
+
+    result = solarposition.next_rise_set_ephem(times,
+                                               golden.latitude,
+                                               golden.longitude,
+                                               golden.altitude,
+                                               pressure=0,
+                                               temperature=11,
+                                               horizon='-0:34')
+    # round to nearest minute
+    result_rounded = pd.DataFrame(index=result.index)
+    for col, data in result.iteritems():
+        result_rounded[col] = data.dt.round('min').tz_convert('MST')
+    assert_frame_equal(expected, result_rounded)
+
+    # test with different timezone
+    times = times.tz_convert('UTC')
+    expected = expected.tz_convert('UTC')
+    for col, data in expected.iteritems():
+        expected[col] = data.dt.tz_convert('UTC')
+    result = solarposition.next_rise_set_ephem(times,
+                                               golden.latitude,
+                                               golden.longitude,
+                                               golden.altitude,
+                                               pressure=0,
+                                               temperature=11,
+                                               horizon='-0:34')
+    # round to nearest minute
+    result_rounded = pd.DataFrame(index=result.index)
+    for col, data in result.iteritems():
+        result_rounded[col] = data.dt.round('min').tz_convert(times.tz)
+    assert_frame_equal(expected, result_rounded)
+
 
 @requires_ephem
 def test_pyephem_physical(expected_solpos):

From e318bad4b77a6d6f25de1e1e306caf8c8bb703b6 Mon Sep 17 00:00:00 2001
From: Cliff Hansen <cwhanse@sandia.gov>
Date: Mon, 24 Sep 2018 11:02:36 -0600
Subject: [PATCH 18/33] Remove dtype from expected...spa

---
 pvlib/test/test_solarposition.py | 14 ++++++--------
 1 file changed, 6 insertions(+), 8 deletions(-)

diff --git a/pvlib/test/test_solarposition.py b/pvlib/test/test_solarposition.py
index be8ba3a0d1..1275313c86 100644
--- a/pvlib/test/test_solarposition.py
+++ b/pvlib/test/test_solarposition.py
@@ -66,8 +66,7 @@ def expected_rise_set_spa():
     return pd.DataFrame({'transit': transit,
                          'sunrise': sunrise,
                          'sunset': sunset},
-                        index=times,
-                        dtype='datetime64[ns]')
+                        index=times)
 
 
 @pytest.fixture()
@@ -199,10 +198,9 @@ def test_get_sun_rise_set_transit(expected_rise_set_spa):
     assert_frame_equal(frame, result_rounded)
 
     # test for Golden, CO compare to NREL SPA
-    result = solarposition.get_sun_rise_set_transit(expected_rise_set_spa.index,
-                                                    golden.latitude,
-                                                    golden.longitude,
-                                                    delta_t=65.0)
+    result = solarposition.get_sun_rise_set_transit(
+            expected_rise_set_spa.index, golden.latitude, golden.longitude,
+            delta_t=65.0)
 
     # round to nearest minute
     result_rounded = pd.DataFrame(index=result.index)
@@ -239,12 +237,12 @@ def test_next_rise_set_ephem(expected_rise_set_ephem):
     expected = pd.DataFrame(index=times,
                             columns=['sunrise', 'sunset'],
                             dtype='datetime64[ns]')
-    expected['sunrise'] = pd.Series(index=times, data = \
+    expected['sunrise'] = pd.Series(index=times, data =
        [expected_rise_set_ephem.loc[datetime.datetime(2015, 1, 2), 'sunrise'],
         expected_rise_set_ephem.loc[datetime.datetime(2015, 1, 3), 'sunrise'],
         expected_rise_set_ephem.loc[datetime.datetime(2015, 1, 3), 'sunrise'],
         expected_rise_set_ephem.loc[datetime.datetime(2015, 1, 3), 'sunrise']])
-    expected['sunset'] = pd.Series(index=times, data = \
+    expected['sunset'] = pd.Series(index=times, data =
        [expected_rise_set_ephem.loc[datetime.datetime(2015, 1, 2), 'sunset'],
         expected_rise_set_ephem.loc[datetime.datetime(2015, 1, 2), 'sunset'],
         expected_rise_set_ephem.loc[datetime.datetime(2015, 1, 2), 'sunset'],

From a88a5b6218a6af4a77395d7d1de2957693e7e240 Mon Sep 17 00:00:00 2001
From: Cliff Hansen <cwhanse@sandia.gov>
Date: Fri, 28 Sep 2018 15:42:35 -0600
Subject: [PATCH 19/33] Add previous rise/set capability

---
 pvlib/solarposition.py           |  93 +++++++++++++++++++++++++---
 pvlib/test/test_solarposition.py | 103 +++++++++++++++++++++----------
 2 files changed, 157 insertions(+), 39 deletions(-)

diff --git a/pvlib/solarposition.py b/pvlib/solarposition.py
index 2608e9f241..c6895f4c0e 100644
--- a/pvlib/solarposition.py
+++ b/pvlib/solarposition.py
@@ -473,11 +473,86 @@ def _ephem_setup(latitude, longitude, altitude, pressure, temperature,
     return obs, sun
 
 
-def next_rise_set_ephem(time, latitude, longitude, altitude=0,
-                        pressure=101325, temperature=12, horizon='0:00'):
+def get_rise_set_ephem(time, latitude, longitude,
+                       next_or_previous='next',
+                       altitude=0,
+                       pressure=101325, temperature=12, horizon='0:00'):
     """
     Calculate the next sunrise and sunset times using the PyEphem package.
 
+    Parameters
+    ----------
+    time : pandas.DatetimeIndex
+        Localized or UTC.
+    latitude : float
+        positive is north of 0
+    longitude : float
+        positive is east of 0
+    next_or_previous : str
+        'next' or 'previous' sunrise and sunset relative to time
+    altitude : float, default 0
+        distance above sea level in meters.
+    pressure : int or float, optional, default 101325
+        air pressure in Pascals.
+    temperature : int or float, optional, default 12
+        air temperature in degrees C.
+    horizon : string, format +/-X:YY
+        arc degrees:arc minutes from geometrical horizon for sunrise and
+        sunset, e.g., horizon='-0:34' when the sun's upper edge crosses the
+        geometrical horizon
+
+    Returns
+    -------
+    pandas.DataFrame
+        index is the same as input time.index
+        columns are 'sunrise' and 'sunset', times are localized to the
+        timezone time.tz
+
+    See also
+    --------
+    pyephem
+    """
+
+    try:
+        import ephem
+    except ImportError:
+        raise ImportError('PyEphem must be installed')
+
+    # if localized, convert to UTC. otherwise, assume UTC.
+    try:
+        time_utc = time.tz_convert('UTC')
+    except TypeError:
+        time_utc = time
+
+    obs, sun = _ephem_setup(latitude, longitude, altitude,
+                            pressure, temperature, horizon)
+    # create lists of sunrise and sunset time localized to time.tz
+    if next_or_previous.lower() == 'next':
+        rising = obs.next_rising
+        setting = obs.next_setting
+    elif next_or_previous.lower() == 'previous':
+        rising = obs.previous_rising
+        setting = obs.previous_setting
+    else:
+        raise ValueError("next_or_previous must be either 'next' or" +
+                         " 'previous'")
+
+    sunrise = []
+    sunset = []
+    for thetime in time_utc:
+        obs.date = ephem.Date(thetime)
+        sunrise.append(_ephem_to_timezone(rising(sun), time.tz))
+        sunset.append(_ephem_to_timezone(setting(sun), time.tz))
+
+    return pd.DataFrame(index=time, data={'sunrise': sunrise,
+                                          'sunset': sunset})
+
+
+def previous_rise_set_ephem(time, latitude, longitude, altitude=0,
+                        pressure=101325, temperature=12, horizon='0:00'):
+    """
+    Calculate the previous sunrise and sunset times using the PyEphem package.
+
     Parameters
     ----------
     time : pandas.DatetimeIndex
@@ -523,15 +598,17 @@ def next_rise_set_ephem(time, latitude, longitude, altitude=0,
     obs, sun = _ephem_setup(latitude, longitude, altitude,
                             pressure, temperature, horizon)
     # create lists of the next sunrise and sunset time localized to time.tz
-    next_sunrise = []
-    next_sunset = []
+    previous_sunrise = []
+    previous_sunset = []
     for thetime in time_utc:
         obs.date = ephem.Date(thetime)
-        next_sunrise.append(_ephem_to_timezone(obs.next_rising(sun), time.tz))
-        next_sunset.append(_ephem_to_timezone(obs.next_setting(sun), time.tz))
+        previous_sunrise.append(_ephem_to_timezone(obs.previous_rising(sun),
+                                                   time.tz))
+        previous_sunset.append(_ephem_to_timezone(obs.previous_setting(sun),
+                                                  time.tz))
 
-    return pd.DataFrame(index=time, data={'sunrise': next_sunrise,
-                                          'sunset': next_sunset})
+    return pd.DataFrame(index=time, data={'sunrise': previous_sunrise,
+                                          'sunset': previous_sunset})
 
 
 def pyephem(time, latitude, longitude, altitude=0, pressure=101325,
diff --git a/pvlib/test/test_solarposition.py b/pvlib/test/test_solarposition.py
index 1275313c86..2ff18c2f20 100644
--- a/pvlib/test/test_solarposition.py
+++ b/pvlib/test/test_solarposition.py
@@ -72,19 +72,23 @@ def expected_rise_set_spa():
 @pytest.fixture()
 def expected_rise_set_ephem():
     # for Golden, CO, from USNO websites
-    times = pd.DatetimeIndex([datetime.datetime(2015, 1, 2),
+    times = pd.DatetimeIndex([datetime.datetime(2015, 1, 1),
+                              datetime.datetime(2015, 1, 2),
                               datetime.datetime(2015, 1, 3),
                               datetime.datetime(2015, 8, 2),
                               ]).tz_localize('MST')
     sunrise = pd.DatetimeIndex([datetime.datetime(2015, 1, 2, 7, 22, 0),
+                                datetime.datetime(2015, 1, 2, 7, 22, 0),
                                 datetime.datetime(2015, 1, 3, 7, 22, 0),
                                 datetime.datetime(2015, 8, 2, 5, 0, 0)
                                 ]).tz_localize('MST').tolist()
-    sunset = pd.DatetimeIndex([datetime.datetime(2015, 1, 2, 16, 48, 0),
+    sunset = pd.DatetimeIndex([datetime.datetime(2015, 1, 2, 16, 47, 0),
+                               datetime.datetime(2015, 1, 2, 16, 48, 0),
                                datetime.datetime(2015, 1, 3, 16, 49, 0),
                                datetime.datetime(2015, 8, 2, 19, 13, 0)
                                ]).tz_localize('MST').tolist()
-    transit = pd.DatetimeIndex([datetime.datetime(2015, 1, 2, 12, 5, 0),
+    transit = pd.DatetimeIndex([datetime.datetime(2015, 1, 2, 12, 4, 0),
+                                datetime.datetime(2015, 1, 2, 12, 5, 0),
                                 datetime.datetime(2015, 1, 3, 12, 5, 0),
                                 datetime.datetime(2015, 8, 2, 12, 7, 0)
                                 ]).tz_localize('MST').tolist()
@@ -199,8 +203,8 @@ def test_get_sun_rise_set_transit(expected_rise_set_spa):
 
     # test for Golden, CO compare to NREL SPA
     result = solarposition.get_sun_rise_set_transit(
-            expected_rise_set_spa.index, golden.latitude, golden.longitude,
-            delta_t=65.0)
+        expected_rise_set_spa.index, golden.latitude, golden.longitude,
+        delta_t=65.0)
 
     # round to nearest minute
     result_rounded = pd.DataFrame(index=result.index)
@@ -212,15 +216,16 @@ def test_get_sun_rise_set_transit(expected_rise_set_spa):
 
 
 @requires_ephem
-def test_next_rise_set_ephem(expected_rise_set_ephem):
-    # test for Golden, CO compare to USNO
-    result = solarposition.next_rise_set_ephem(expected_rise_set_ephem.index,
-                                               golden.latitude,
-                                               golden.longitude,
-                                               golden.altitude,
-                                               pressure=0,
-                                               temperature=11,
-                                               horizon='-0:34')
+def test_get_rise_set_ephem(expected_rise_set_ephem):
+    # test for Golden, CO compare to USNO, using local midnight
+    result = solarposition.get_rise_set_ephem(expected_rise_set_ephem.index,
+                                              golden.latitude,
+                                              golden.longitude,
+                                              next_or_previous='next',
+                                              golden.altitude,
+                                              pressure=0,
+                                              temperature=11,
+                                              horizon='-0:34')
     # round to nearest minute
     result_rounded = pd.DataFrame(index=result.index)
     for col, data in result.iteritems():
@@ -228,7 +233,7 @@ def test_next_rise_set_ephem(expected_rise_set_ephem):
     del expected_rise_set_ephem['transit']
     assert_frame_equal(expected_rise_set_ephem, result_rounded)
 
-    # test with times
+    # test next sunrise/sunset with times
     times = pd.DatetimeIndex([datetime.datetime(2015, 1, 2, 3, 0, 0),
                               datetime.datetime(2015, 1, 2, 10, 15, 0),
                               datetime.datetime(2015, 1, 2, 15, 3, 0),
@@ -237,24 +242,59 @@ def test_next_rise_set_ephem(expected_rise_set_ephem):
     expected = pd.DataFrame(index=times,
                             columns=['sunrise', 'sunset'],
                             dtype='datetime64[ns]')
-    expected['sunrise'] = pd.Series(index=times, data =
+    expected['sunrise'] = pd.Series(index=times, data=
        [expected_rise_set_ephem.loc[datetime.datetime(2015, 1, 2), 'sunrise'],
         expected_rise_set_ephem.loc[datetime.datetime(2015, 1, 3), 'sunrise'],
         expected_rise_set_ephem.loc[datetime.datetime(2015, 1, 3), 'sunrise'],
         expected_rise_set_ephem.loc[datetime.datetime(2015, 1, 3), 'sunrise']])
-    expected['sunset'] = pd.Series(index=times, data =
+    expected['sunset'] = pd.Series(index=times, data=
        [expected_rise_set_ephem.loc[datetime.datetime(2015, 1, 2), 'sunset'],
         expected_rise_set_ephem.loc[datetime.datetime(2015, 1, 2), 'sunset'],
         expected_rise_set_ephem.loc[datetime.datetime(2015, 1, 2), 'sunset'],
         expected_rise_set_ephem.loc[datetime.datetime(2015, 1, 3), 'sunset']])
 
-    result = solarposition.next_rise_set_ephem(times,
-                                               golden.latitude,
-                                               golden.longitude,
-                                               golden.altitude,
-                                               pressure=0,
-                                               temperature=11,
-                                               horizon='-0:34')
+    result = solarposition.get_rise_set_ephem(times,
+                                              golden.latitude,
+                                              golden.longitude,
+                                              next_or_previous='next',
+                                              golden.altitude,
+                                              pressure=0,
+                                              temperature=11,
+                                              horizon='-0:34')
+    # round to nearest minute
+    result_rounded = pd.DataFrame(index=result.index)
+    for col, data in result.iteritems():
+        result_rounded[col] = data.dt.round('min').tz_convert('MST')
+    assert_frame_equal(expected, result_rounded)
+
+    # test previous sunrise/sunset with times
+    times = pd.DatetimeIndex([datetime.datetime(2015, 1, 2, 3, 0, 0),
+                              datetime.datetime(2015, 1, 2, 10, 15, 0),
+                              datetime.datetime(2015, 1, 3, 3, 0, 0),
+                              datetime.datetime(2015, 1, 3, 13, 6, 7)
+                              ]).tz_localize('MST')
+    expected = pd.DataFrame(index=times,
+                            columns=['sunrise', 'sunset'],
+                            dtype='datetime64[ns]')
+    expected['sunrise'] = pd.Series(index=times, data=
+       [expected_rise_set_ephem.loc[datetime.datetime(2015, 1, 1), 'sunrise'],
+        expected_rise_set_ephem.loc[datetime.datetime(2015, 1, 2), 'sunrise'],
+        expected_rise_set_ephem.loc[datetime.datetime(2015, 1, 2), 'sunrise'],
+        expected_rise_set_ephem.loc[datetime.datetime(2015, 1, 3), 'sunrise']])
+    expected['sunset'] = pd.Series(index=times, data=
+       [expected_rise_set_ephem.loc[datetime.datetime(2015, 1, 1), 'sunset'],
+        expected_rise_set_ephem.loc[datetime.datetime(2015, 1, 1), 'sunset'],
+        expected_rise_set_ephem.loc[datetime.datetime(2015, 1, 2), 'sunset'],
+        expected_rise_set_ephem.loc[datetime.datetime(2015, 1, 2), 'sunset']])
+
+    result = solarposition.get_rise_set_ephem(times,
+                                              golden.latitude,
+                                              golden.longitude,
+                                              next_or_previous='previous',
+                                              golden.altitude,
+                                              pressure=0,
+                                              temperature=11,
+                                              horizon='-0:34')
     # round to nearest minute
     result_rounded = pd.DataFrame(index=result.index)
     for col, data in result.iteritems():
@@ -266,13 +306,14 @@ def test_next_rise_set_ephem(expected_rise_set_ephem):
     expected = expected.tz_convert('UTC')
     for col, data in expected.iteritems():
         expected[col] = data.dt.tz_convert('UTC')
-    result = solarposition.next_rise_set_ephem(times,
-                                               golden.latitude,
-                                               golden.longitude,
-                                               golden.altitude,
-                                               pressure=0,
-                                               temperature=11,
-                                               horizon='-0:34')
+    result = solarposition.get_rise_set_ephem(times,
+                                              golden.latitude,
+                                              golden.longitude,
+                                              next_or_previous='next',
+                                              golden.altitude,
+                                              pressure=0,
+                                              temperature=11,
+                                              horizon='-0:34')
     # round to nearest minute
     result_rounded = pd.DataFrame(index=result.index)
     for col, data in result.iteritems():

From 2121aa0ac80561bba7e2bf1050f3e6e6b629c261 Mon Sep 17 00:00:00 2001
From: Cliff Hansen <cwhanse@sandia.gov>
Date: Fri, 28 Sep 2018 15:46:49 -0600
Subject: [PATCH 20/33] style fixes

---
 pvlib/test/test_solarposition.py | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/pvlib/test/test_solarposition.py b/pvlib/test/test_solarposition.py
index 2ff18c2f20..f292e62274 100644
--- a/pvlib/test/test_solarposition.py
+++ b/pvlib/test/test_solarposition.py
@@ -222,7 +222,7 @@ def test_get_rise_set_ephem(expected_rise_set_ephem):
                                               golden.latitude,
                                               golden.longitude,
                                               next_or_previous='next',
-                                              golden.altitude,
+                                              altitude=golden.altitude,
                                               pressure=0,
                                               temperature=11,
                                               horizon='-0:34')
@@ -257,7 +257,7 @@ def test_get_rise_set_ephem(expected_rise_set_ephem):
                                               golden.latitude,
                                               golden.longitude,
                                               next_or_previous='next',
-                                              golden.altitude,
+                                              altitude=golden.altitude,
                                               pressure=0,
                                               temperature=11,
                                               horizon='-0:34')
@@ -291,7 +291,7 @@ def test_get_rise_set_ephem(expected_rise_set_ephem):
                                               golden.latitude,
                                               golden.longitude,
                                               next_or_previous='previous',
-                                              golden.altitude,
+                                              altitude=golden.altitude,
                                               pressure=0,
                                               temperature=11,
                                               horizon='-0:34')
@@ -310,7 +310,7 @@ def test_get_rise_set_ephem(expected_rise_set_ephem):
                                               golden.latitude,
                                               golden.longitude,
                                               next_or_previous='next',
-                                              golden.altitude,
+                                              altitude=golden.altitude,
                                               pressure=0,
                                               temperature=11,
                                               horizon='-0:34')

From c75b10e47798d734dc5478f7ead1888145fbdc6d Mon Sep 17 00:00:00 2001
From: Cliff Hansen <cwhanse@sandia.gov>
Date: Fri, 28 Sep 2018 16:42:38 -0600
Subject: [PATCH 21/33] Fix expected result

---
 pvlib/test/test_solarposition.py | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/pvlib/test/test_solarposition.py b/pvlib/test/test_solarposition.py
index f292e62274..5e564ef863 100644
--- a/pvlib/test/test_solarposition.py
+++ b/pvlib/test/test_solarposition.py
@@ -77,17 +77,17 @@ def expected_rise_set_ephem():
                               datetime.datetime(2015, 1, 3),
                               datetime.datetime(2015, 8, 2),
                               ]).tz_localize('MST')
-    sunrise = pd.DatetimeIndex([datetime.datetime(2015, 1, 2, 7, 22, 0),
+    sunrise = pd.DatetimeIndex([datetime.datetime(2015, 1, 1, 7, 22, 0),
                                 datetime.datetime(2015, 1, 2, 7, 22, 0),
                                 datetime.datetime(2015, 1, 3, 7, 22, 0),
                                 datetime.datetime(2015, 8, 2, 5, 0, 0)
                                 ]).tz_localize('MST').tolist()
-    sunset = pd.DatetimeIndex([datetime.datetime(2015, 1, 2, 16, 47, 0),
+    sunset = pd.DatetimeIndex([datetime.datetime(2015, 1, 1, 16, 47, 0),
                                datetime.datetime(2015, 1, 2, 16, 48, 0),
                                datetime.datetime(2015, 1, 3, 16, 49, 0),
                                datetime.datetime(2015, 8, 2, 19, 13, 0)
                                ]).tz_localize('MST').tolist()
-    transit = pd.DatetimeIndex([datetime.datetime(2015, 1, 2, 12, 4, 0),
+    transit = pd.DatetimeIndex([datetime.datetime(2015, 1, 1, 12, 4, 0),
                                 datetime.datetime(2015, 1, 2, 12, 5, 0),
                                 datetime.datetime(2015, 1, 3, 12, 5, 0),
                                 datetime.datetime(2015, 8, 2, 12, 7, 0)

From f85a46a75c718f1d9ae6da3a2673c46c85f79110 Mon Sep 17 00:00:00 2001
From: Cliff Hansen <cwhanse@sandia.gov>
Date: Fri, 28 Sep 2018 21:26:14 -0600
Subject: [PATCH 22/33] Fix timezone test

---
 pvlib/test/test_solarposition.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/pvlib/test/test_solarposition.py b/pvlib/test/test_solarposition.py
index 5e564ef863..27c516577e 100644
--- a/pvlib/test/test_solarposition.py
+++ b/pvlib/test/test_solarposition.py
@@ -303,13 +303,13 @@ def test_get_rise_set_ephem(expected_rise_set_ephem):
 
     # test with different timezone
     times = times.tz_convert('UTC')
-    expected = expected.tz_convert('UTC')
+    expected = expected.tz_convert('UTC') # resuse result from previous
     for col, data in expected.iteritems():
         expected[col] = data.dt.tz_convert('UTC')
     result = solarposition.get_rise_set_ephem(times,
                                               golden.latitude,
                                               golden.longitude,
-                                              next_or_previous='next',
+                                              next_or_previous='previous',
                                               altitude=golden.altitude,
                                               pressure=0,
                                               temperature=11,

From 6238321847c679fa0dd85fd7175de1acb5b81a14 Mon Sep 17 00:00:00 2001
From: Cliff Hansen <cwhanse@sandia.gov>
Date: Sat, 29 Sep 2018 09:40:36 -0600
Subject: [PATCH 23/33] Documentation updates

---
 docs/sphinx/source/api.rst             | 1 +
 docs/sphinx/source/whatsnew/v0.6.1.rst | 4 +++-
 2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/docs/sphinx/source/api.rst b/docs/sphinx/source/api.rst
index 0b9a8e20e4..ce28728517 100644
--- a/docs/sphinx/source/api.rst
+++ b/docs/sphinx/source/api.rst
@@ -55,6 +55,7 @@ Additional functions for quantities closely related to solar position.
    solarposition.calc_time
    solarposition.pyephem_earthsun_distance
    solarposition.nrel_earthsun_distance
+   solarposition.get_rise_set_ephem
    spa.calculate_deltat
 
 The spa module contains the implementation of the built-in NREL SPA
diff --git a/docs/sphinx/source/whatsnew/v0.6.1.rst b/docs/sphinx/source/whatsnew/v0.6.1.rst
index 37f8ee312a..8f0aefcc0d 100644
--- a/docs/sphinx/source/whatsnew/v0.6.1.rst
+++ b/docs/sphinx/source/whatsnew/v0.6.1.rst
@@ -16,6 +16,7 @@ API Changes
 
 Enhancements
 ~~~~~~~~~~~~
+* :func:`~pvlib.solarposition.get_rise_set_ephem` returns sunrise and sunset times using pyephem
 
 
 Bug fixes
@@ -29,4 +30,5 @@ Testing
 
 Contributors
 ~~~~~~~~~~~~
-* Will Holmgren (:ghuser:`wholmgren`)
\ No newline at end of file
+* Will Holmgren (:ghuser:`wholmgren`)
+* Cliff Hansen (:ghuser:`cwhanse`)

From 36180223fc819106b11dd8fae8f9e898094c7479 Mon Sep 17 00:00:00 2001
From: Cliff Hansen <cwhanse@sandia.gov>
Date: Sat, 29 Sep 2018 09:41:24 -0600
Subject: [PATCH 24/33] Fix spacing

---
 pvlib/solarposition.py | 63 ------------------------------------------
 1 file changed, 63 deletions(-)

diff --git a/pvlib/solarposition.py b/pvlib/solarposition.py
index c6895f4c0e..f398ba83eb 100644
--- a/pvlib/solarposition.py
+++ b/pvlib/solarposition.py
@@ -548,69 +548,6 @@ def get_rise_set_ephem(time, latitude, longitude,
                                           'sunset': sunset})
 
 
-def previous_rise_set_ephem(time, latitude, longitude, altitude=0,
-                        pressure=101325, temperature=12, horizon='0:00'):
-    """
-    Calculate the previous sunrise and sunset times using the PyEphem package.
-
-    Parameters
-    ----------
-    time : pandas.DatetimeIndex
-        Localized or UTC.
-    latitude : float
-        positive is north of 0
-    longitude : float
-        positive is east of 0
-    altitude : float, default 0
-        distance above sea level in meters.
-    pressure : int or float, optional, default 101325
-        air pressure in Pascals.
-    temperature : int or float, optional, default 12
-        air temperature in degrees C.
-    horizon : string, format +/-X:YY
-        arc degrees:arc minutes from geometrical horizon for sunrise and
-        sunset, e.g., horizon='-0:34' when the sun's upper edge crosses the
-        geometrical horizon
-
-    Returns
-    -------
-    pandas.DataFrame
-        index is the same as input time.index
-        columns are 'sunrise' and 'sunset', times are localized to the
-        timezone time.tz
-
-    See also
-    --------
-    pyephem
-    """
-
-    try:
-        import ephem
-    except ImportError:
-        raise ImportError('PyEphem must be installed')
-
-    # if localized, convert to UTC. otherwise, assume UTC.
-    try:
-        time_utc = time.tz_convert('UTC')
-    except TypeError:
-        time_utc = time
-
-    obs, sun = _ephem_setup(latitude, longitude, altitude,
-                            pressure, temperature, horizon)
-    # create lists of the next sunrise and sunset time localized to time.tz
-    previous_sunrise = []
-    previous_sunset = []
-    for thetime in time_utc:
-        obs.date = ephem.Date(thetime)
-        previous_sunrise.append(_ephem_to_timezone(obs.previous_rising(sun),
-                                                   time.tz))
-        previous_sunset.append(_ephem_to_timezone(obs.previous_setting(sun),
-                                                  time.tz))
-
-    return pd.DataFrame(index=time, data={'sunrise': previous_sunrise,
-                                          'sunset': previous_sunset})
-
-
 def pyephem(time, latitude, longitude, altitude=0, pressure=101325,
             temperature=12, horizon='+0:00'):
     """

From 36bf3cc57d72e18462aaf447247dc1bcff40dc50 Mon Sep 17 00:00:00 2001
From: Cliff Hansen <cwhanse@sandia.gov>
Date: Sun, 30 Sep 2018 13:16:20 -0600
Subject: [PATCH 25/33] Add transit, change golden to fixture, add horizon
 kwarg and error tests

---
 pvlib/solarposition.py           |  41 ++++----
 pvlib/test/test_solarposition.py | 156 ++++++++++++++++++++-----------
 2 files changed, 127 insertions(+), 70 deletions(-)

diff --git a/pvlib/solarposition.py b/pvlib/solarposition.py
index f398ba83eb..f687dda838 100644
--- a/pvlib/solarposition.py
+++ b/pvlib/solarposition.py
@@ -6,6 +6,7 @@
 # Rob Andrews (@Calama-Consulting), Calama Consulting, 2014
 # Will Holmgren (@wholmgren), University of Arizona, 2014
 # Tony Lorenzo (@alorenzo175), University of Arizona, 2015
+# Cliff hansen (@cwhanse), Sandia National Laboratories, 2018
 
 from __future__ import division
 import os
@@ -473,17 +474,17 @@ def _ephem_setup(latitude, longitude, altitude, pressure, temperature,
     return obs, sun
 
 
-def get_rise_set_ephem(time, latitude, longitude,
-                       next_or_previous='next',
-                       altitude=0,
-                       pressure=101325, temperature=12, horizon='0:00'):
+def rise_set_transit_ephem(time, latitude, longitude,
+                           next_or_previous='next',
+                           altitude=0,
+                           pressure=101325, temperature=12, horizon='0:00'):
     """
     Calculate the next sunrise and sunset times using the PyEphem package.
 
     Parameters
     ----------
     time : pandas.DatetimeIndex
-        Localized or UTC.
+        Must be localized
     latitude : float
         positive is north of 0
     longitude : float
@@ -498,15 +499,16 @@ def get_rise_set_ephem(time, latitude, longitude,
         air temperature in degrees C.
     horizon : string, format +/-X:YY
         arc degrees:arc minutes from geometrical horizon for sunrise and
-        sunset, e.g., horizon='-0:34' when the sun's upper edge crosses the
+        sunset, e.g., horizon='+0:00' to use sun center crossing the
+        geometrical horizon to define sunrise and sunset,
+        horizon='-0:34' for when the sun's upper edge crosses the
         geometrical horizon
 
     Returns
     -------
     pandas.DataFrame
-        index is the same as input time.index
-        columns are 'sunrise' and 'sunset', times are localized to the
-        timezone time.tz
+        index is the same as input `time` argument
+        columns are 'sunrise', 'sunset', and 'transit'
 
     See also
     --------
@@ -518,11 +520,9 @@ def get_rise_set_ephem(time, latitude, longitude,
     except ImportError:
         raise ImportError('PyEphem must be installed')
 
-    # if localized, convert to UTC. otherwise, assume UTC.
-    try:
-        time_utc = time.tz_convert('UTC')
-    except TypeError:
-        time_utc = time
+    # times must be localized
+    if not time.tz:
+        raise ValueError('rise_set_ephem: times must be localized')
 
     obs, sun = _ephem_setup(latitude, longitude, altitude,
                             pressure, temperature, horizon)
@@ -539,7 +539,7 @@ def get_rise_set_ephem(time, latitude, longitude,
 
     sunrise = []
     sunset = []
-    for thetime in time_utc:
+    for thetime in time:
         obs.date = ephem.Date(thetime)
         sunrise.append(_ephem_to_timezone(rising(sun), time.tz))
         sunset.append(_ephem_to_timezone(setting(sun), time.tz))
@@ -569,12 +569,15 @@ def pyephem(time, latitude, longitude, altitude=0, pressure=101325,
         air temperature in degrees C.
     horizon : string, optional, default '+0:00'
         arc degrees:arc minutes from geometrical horizon for sunrise and
-        sunset, e.g., horizon='-0:34' when the sun's upper edge crosses the
+        sunset, e.g., horizon='+0:00' to use sun center crossing the
+        geometrical horizon to define sunrise and sunset,
+        horizon='-0:34' for when the sun's upper edge crosses the
         geometrical horizon
 
     Returns
     -------
-    DataFrame
+    pandas.DataFrame
+        index is the same as input `time` argument
         The DataFrame will have the following columns:
         apparent_elevation, elevation,
         apparent_azimuth, azimuth,
@@ -840,7 +843,9 @@ def calc_time(lower_bound, upper_bound, latitude, longitude, attribute, value,
         Air temperature in degrees C.
     horizon : string, optional, default '+0:00'
         arc degrees:arc minutes from geometrical horizon for sunrise and
-        sunset, e.g., horizon='-0:34' when the sun's upper edge crosses the
+        sunset, e.g., horizon='+0:00' to use sun center crossing the
+        geometrical horizon to define sunrise and sunset,
+        horizon='-0:34' for when the sun's upper edge crosses the
         geometrical horizon
     xtol : float, optional, default 1.0e-12
         The allowed error in the result from value
diff --git a/pvlib/test/test_solarposition.py b/pvlib/test/test_solarposition.py
index 27c516577e..e83916d93c 100644
--- a/pvlib/test/test_solarposition.py
+++ b/pvlib/test/test_solarposition.py
@@ -21,15 +21,21 @@
                       end=datetime.datetime(2014,6,26), freq='15Min')
 
 tus = Location(32.2, -111, 'US/Arizona', 700) # no DST issues possible
-# In 2003, DST in US was from April 6 to October 26
-golden_mst = Location(39.742476, -105.1786, 'MST', 1830.14) # no DST issues possible
-golden = Location(39.742476, -105.1786, 'America/Denver', 1830.14) # DST issues possible
-
 times_localized = times.tz_localize(tus.tz)
 
 tol = 5
 
 
+@pytest.fixture()
+def golden():
+    return Location(39.742476, -105.1786, 'America/Denver', 1830.14)
+
+
+@pytest.fixture()
+def golden_mst():
+    return Location(39.742476, -105.1786, 'MST', 1830.14)
+
+
 @pytest.fixture()
 def expected_solpos():
     return pd.DataFrame({'elevation': 39.872046,
@@ -101,7 +107,7 @@ def expected_rise_set_ephem():
 # this doesn't mean that one code is better than the other.
 
 @requires_spa_c
-def test_spa_c_physical(expected_solpos):
+def test_spa_c_physical(expected_solpos, golden_mst):
     times = pd.date_range(datetime.datetime(2003,10,17,12,30,30),
                           periods=1, freq='D', tz=golden_mst.tz)
     ephem_data = solarposition.spa_c(times, golden_mst.latitude,
@@ -113,7 +119,7 @@ def test_spa_c_physical(expected_solpos):
 
 
 @requires_spa_c
-def test_spa_c_physical_dst(expected_solpos):
+def test_spa_c_physical_dst(expected_solpos, golden):
     times = pd.date_range(datetime.datetime(2003,10,17,13,30,30),
                           periods=1, freq='D', tz=golden.tz)
     ephem_data = solarposition.spa_c(times, golden.latitude,
@@ -123,7 +129,7 @@ def test_spa_c_physical_dst(expected_solpos):
     expected_solpos.index = times
     assert_frame_equal(expected_solpos, ephem_data[expected_solpos.columns])
 
-def test_spa_python_numpy_physical(expected_solpos):
+def test_spa_python_numpy_physical(expected_solpos, golden):
     times = pd.date_range(datetime.datetime(2003,10,17,12,30,30),
                           periods=1, freq='D', tz=golden_mst.tz)
     ephem_data = solarposition.spa_python(times, golden_mst.latitude,
@@ -135,7 +141,7 @@ def test_spa_python_numpy_physical(expected_solpos):
     expected_solpos.index = times
     assert_frame_equal(expected_solpos, ephem_data[expected_solpos.columns])
 
-def test_spa_python_numpy_physical_dst(expected_solpos):
+def test_spa_python_numpy_physical_dst(expected_solpos, golden):
     times = pd.date_range(datetime.datetime(2003,10,17,13,30,30),
                           periods=1, freq='D', tz=golden.tz)
     ephem_data = solarposition.spa_python(times, golden.latitude,
@@ -149,7 +155,7 @@ def test_spa_python_numpy_physical_dst(expected_solpos):
 
 
 @requires_numba
-def test_spa_python_numba_physical(expected_solpos):
+def test_spa_python_numba_physical(expected_solpos, golden_mst):
     times = pd.date_range(datetime.datetime(2003,10,17,12,30,30),
                           periods=1, freq='D', tz=golden_mst.tz)
     ephem_data = solarposition.spa_python(times, golden_mst.latitude,
@@ -163,7 +169,7 @@ def test_spa_python_numba_physical(expected_solpos):
 
 
 @requires_numba
-def test_spa_python_numba_physical_dst(expected_solpos):
+def test_spa_python_numba_physical_dst(expected_solpos, golden):
     times = pd.date_range(datetime.datetime(2003,10,17,13,30,30),
                           periods=1, freq='D', tz=golden.tz)
     ephem_data = solarposition.spa_python(times, golden.latitude,
@@ -176,7 +182,7 @@ def test_spa_python_numba_physical_dst(expected_solpos):
 
 
 @needs_pandas_0_17
-def test_get_sun_rise_set_transit(expected_rise_set_spa):
+def test_get_sun_rise_set_transit(expected_rise_set_spa, golden):
     south = Location(-35.0, 0.0, tz='UTC')
     times = pd.DatetimeIndex([datetime.datetime(1996, 7, 5, 0),
                               datetime.datetime(2004, 12, 4, 0)]
@@ -216,9 +222,10 @@ def test_get_sun_rise_set_transit(expected_rise_set_spa):
 
 
 @requires_ephem
-def test_get_rise_set_ephem(expected_rise_set_ephem):
+def test_rise_set_transit_ephem(expected_rise_set_ephem, golden):
     # test for Golden, CO compare to USNO, using local midnight
-    result = solarposition.get_rise_set_ephem(expected_rise_set_ephem.index,
+    result = solarposition.rise_set_transit_ephem(
+                                              expected_rise_set_ephem.index,
                                               golden.latitude,
                                               golden.longitude,
                                               next_or_previous='next',
@@ -230,7 +237,6 @@ def test_get_rise_set_ephem(expected_rise_set_ephem):
     result_rounded = pd.DataFrame(index=result.index)
     for col, data in result.iteritems():
         result_rounded[col] = data.dt.round('min').tz_convert('MST')
-    del expected_rise_set_ephem['transit']
     assert_frame_equal(expected_rise_set_ephem, result_rounded)
 
     # test next sunrise/sunset with times
@@ -252,15 +258,20 @@ def test_get_rise_set_ephem(expected_rise_set_ephem):
         expected_rise_set_ephem.loc[datetime.datetime(2015, 1, 2), 'sunset'],
         expected_rise_set_ephem.loc[datetime.datetime(2015, 1, 2), 'sunset'],
         expected_rise_set_ephem.loc[datetime.datetime(2015, 1, 3), 'sunset']])
-
-    result = solarposition.get_rise_set_ephem(times,
-                                              golden.latitude,
-                                              golden.longitude,
-                                              next_or_previous='next',
-                                              altitude=golden.altitude,
-                                              pressure=0,
-                                              temperature=11,
-                                              horizon='-0:34')
+    expected['transit'] = pd.Series(index=times, data=
+       [expected_rise_set_ephem.loc[datetime.datetime(2015, 1, 2), 'transit'],
+        expected_rise_set_ephem.loc[datetime.datetime(2015, 1, 2), 'transit'],
+        expected_rise_set_ephem.loc[datetime.datetime(2015, 1, 3), 'transit'],
+        expected_rise_set_ephem.loc[datetime.datetime(2015, 1, 3), 'transit']])
+
+    result = solarposition.rise_set_transit_ephem(times,
+                                                  golden.latitude,
+                                                  golden.longitude,
+                                                  next_or_previous='next',
+                                                  altitude=golden.altitude,
+                                                  pressure=0,
+                                                  temperature=11,
+                                                  horizon='-0:34')
     # round to nearest minute
     result_rounded = pd.DataFrame(index=result.index)
     for col, data in result.iteritems():
@@ -286,15 +297,20 @@ def test_get_rise_set_ephem(expected_rise_set_ephem):
         expected_rise_set_ephem.loc[datetime.datetime(2015, 1, 1), 'sunset'],
         expected_rise_set_ephem.loc[datetime.datetime(2015, 1, 2), 'sunset'],
         expected_rise_set_ephem.loc[datetime.datetime(2015, 1, 2), 'sunset']])
-
-    result = solarposition.get_rise_set_ephem(times,
-                                              golden.latitude,
-                                              golden.longitude,
-                                              next_or_previous='previous',
-                                              altitude=golden.altitude,
-                                              pressure=0,
-                                              temperature=11,
-                                              horizon='-0:34')
+    expected['transit'] = pd.Series(index=times, data=
+       [expected_rise_set_ephem.loc[datetime.datetime(2015, 1, 1), 'transit'],
+        expected_rise_set_ephem.loc[datetime.datetime(2015, 1, 1), 'transit'],
+        expected_rise_set_ephem.loc[datetime.datetime(2015, 1, 2), 'transit'],
+        expected_rise_set_ephem.loc[datetime.datetime(2015, 1, 3), 'transit']])
+
+    result = solarposition.rise_set_transit_ephem(times,
+                                                  golden.latitude,
+                                                  golden.longitude,
+                                                  next_or_previous='previous',
+                                                  altitude=golden.altitude,
+                                                  pressure=0,
+                                                  temperature=11,
+                                                  horizon='-0:34')
     # round to nearest minute
     result_rounded = pd.DataFrame(index=result.index)
     for col, data in result.iteritems():
@@ -303,17 +319,17 @@ def test_get_rise_set_ephem(expected_rise_set_ephem):
 
     # test with different timezone
     times = times.tz_convert('UTC')
-    expected = expected.tz_convert('UTC') # resuse result from previous
+    expected = expected.tz_convert('UTC')  # resuse result from previous
     for col, data in expected.iteritems():
         expected[col] = data.dt.tz_convert('UTC')
-    result = solarposition.get_rise_set_ephem(times,
-                                              golden.latitude,
-                                              golden.longitude,
-                                              next_or_previous='previous',
-                                              altitude=golden.altitude,
-                                              pressure=0,
-                                              temperature=11,
-                                              horizon='-0:34')
+    result = solarposition.rise_set_transit_ephem(times,
+                                                  golden.latitude,
+                                                  golden.longitude,
+                                                  next_or_previous='previous',
+                                                  altitude=golden.altitude,
+                                                  pressure=0,
+                                                  temperature=11,
+                                                  horizon='-0:34')
     # round to nearest minute
     result_rounded = pd.DataFrame(index=result.index)
     for col, data in result.iteritems():
@@ -322,7 +338,43 @@ def test_get_rise_set_ephem(expected_rise_set_ephem):
 
 
 @requires_ephem
-def test_pyephem_physical(expected_solpos):
+def test_rise_set_transit_ephem_error(expected_rise_set_ephem, golden):
+    with pytest.raises(ValueError):
+        solarposition.rise_set_transit_ephem(expected_rise_set_ephem.index,
+                                             golden.latitude,
+                                             golden.longitude,
+                                             next_or_previous='other')
+    tz_naive = pd.DatetimeIndex([datetime.datetime(2015, 1, 2, 3, 0, 0)])
+    with pytest.raises(ValueError):
+        solarposition.rise_set_transit_ephem(tz_naive,
+                                             golden.latitude,
+                                             golden.longitude,
+                                             next_or_previous='next')
+
+
+@requires_ephem
+def test_rise_set_transit_ephem_horizon(golden):
+    times = pd.DatetimeIndex([datetime.datetime(2016, 1, 3, 0, 0, 0)
+                             ]).tz_localize('MST')
+    # center of sun disk
+    center = solarposition.rise_set_transit_ephem(times,
+                                                  latitude=golden.latitude,
+                                                  longitude=golden.longitude)
+    edge = solarposition.rise_set_transit_ephem(times,
+                                                latitude=golden.latitude,
+                                                longitude=golden.longitude,
+                                                horizon='-0:34')
+    result_rounded = (edge['sunrise'] - center['sunrise']).dt.round('min')
+
+    sunrise_delta = datetime.datetime(2016, 1, 3, 7, 17, 11) - \
+                    datetime.datetime(2016, 1, 3, 7, 21, 33)
+    expected = pd.Series(index=times,
+                         data=sunrise_delta).dt.round('min')
+    assert_series_equal(expected, result_rounded)
+
+
+@requires_ephem
+def test_pyephem_physical(expected_solpos, golden_mst):
     times = pd.date_range(datetime.datetime(2003,10,17,12,30,30),
                           periods=1, freq='D', tz=golden_mst.tz)
     ephem_data = solarposition.pyephem(times, golden_mst.latitude,
@@ -334,7 +386,7 @@ def test_pyephem_physical(expected_solpos):
 
 
 @requires_ephem
-def test_pyephem_physical_dst(expected_solpos):
+def test_pyephem_physical_dst(expected_solpos, golden):
     times = pd.date_range(datetime.datetime(2003,10,17,13,30,30), periods=1,
                           freq='D', tz=golden.tz)
     ephem_data = solarposition.pyephem(times, golden.latitude,
@@ -380,7 +432,7 @@ def test_earthsun_distance():
     assert_allclose(1, distance, atol=0.1)
 
 
-def test_ephemeris_physical(expected_solpos):
+def test_ephemeris_physical(expected_solpos, golden_mst):
     times = pd.date_range(datetime.datetime(2003,10,17,12,30,30),
                           periods=1, freq='D', tz=golden_mst.tz)
     ephem_data = solarposition.ephemeris(times, golden_mst.latitude,
@@ -393,7 +445,7 @@ def test_ephemeris_physical(expected_solpos):
     assert_frame_equal(expected_solpos, ephem_data[expected_solpos.columns])
 
 
-def test_ephemeris_physical_dst(expected_solpos):
+def test_ephemeris_physical_dst(expected_solpos, golden):
     times = pd.date_range(datetime.datetime(2003,10,17,13,30,30),
                           periods=1, freq='D', tz=golden.tz)
     ephem_data = solarposition.ephemeris(times, golden.latitude,
@@ -405,7 +457,7 @@ def test_ephemeris_physical_dst(expected_solpos):
     assert_frame_equal(expected_solpos, ephem_data[expected_solpos.columns])
 
 
-def test_ephemeris_physical_no_tz(expected_solpos):
+def test_ephemeris_physical_no_tz(expected_solpos, golden_mst):
     times = pd.date_range(datetime.datetime(2003,10,17,19,30,30),
                           periods=1, freq='D')
     ephem_data = solarposition.ephemeris(times, golden_mst.latitude,
@@ -418,7 +470,7 @@ def test_ephemeris_physical_no_tz(expected_solpos):
     assert_frame_equal(expected_solpos, ephem_data[expected_solpos.columns])
 
 
-def test_get_solarposition_error():
+def test_get_solarposition_error(golden):
     times = pd.date_range(datetime.datetime(2003,10,17,13,30,30),
                           periods=1, freq='D', tz=golden.tz)
     with pytest.raises(ValueError):
@@ -439,7 +491,7 @@ def test_get_solarposition_error():
                  'equation_of_time', 'zenith'],
         index=expected_solpos().index))
     ])
-def test_get_solarposition_pressure(pressure, expected):
+def test_get_solarposition_pressure(pressure, expected, golden):
     times = pd.date_range(datetime.datetime(2003,10,17,13,30,30),
                           periods=1, freq='D', tz=golden.tz)
     ephem_data = solarposition.get_solarposition(times, golden.latitude,
@@ -463,7 +515,7 @@ def test_get_solarposition_pressure(pressure, expected):
                  'equation_of_time', 'zenith'],
         index=expected_solpos().index))
     ])
-def test_get_solarposition_altitude(altitude, expected):
+def test_get_solarposition_altitude(altitude, expected, golden):
     times = pd.date_range(datetime.datetime(2003,10,17,13,30,30),
                           periods=1, freq='D', tz=golden.tz)
     ephem_data = solarposition.get_solarposition(times, golden.latitude,
@@ -485,7 +537,7 @@ def test_get_solarposition_altitude(altitude, expected):
     ((None, 'nrel_numba', expected_solpos_multi())),
     (67.0, 'nrel_numba', expected_solpos_multi())
     ])
-def test_get_solarposition_deltat(delta_t, method, expected):
+def test_get_solarposition_deltat(delta_t, method, expected, golden):
     times = pd.date_range(datetime.datetime(2003,10,17,13,30,30),
                           periods=2, freq='D', tz=golden.tz)
     ephem_data = solarposition.get_solarposition(times, golden.latitude,
@@ -501,7 +553,7 @@ def test_get_solarposition_deltat(delta_t, method, expected):
     assert_frame_equal(this_expected, ephem_data[this_expected.columns])
 
 
-def test_get_solarposition_no_kwargs(expected_solpos):
+def test_get_solarposition_no_kwargs(expected_solpos, golden):
     times = pd.date_range(datetime.datetime(2003,10,17,13,30,30),
                           periods=1, freq='D', tz=golden.tz)
     ephem_data = solarposition.get_solarposition(times, golden.latitude,
@@ -513,7 +565,7 @@ def test_get_solarposition_no_kwargs(expected_solpos):
 
 
 @requires_ephem
-def test_get_solarposition_method_pyephem(expected_solpos):
+def test_get_solarposition_method_pyephem(expected_solpos, golden):
     times = pd.date_range(datetime.datetime(2003, 10, 17, 13, 30, 30),
                           periods=1, freq='D', tz=golden.tz)
     ephem_data = solarposition.get_solarposition(times, golden.latitude,

From 39956cc9272b820c579bd7a73c98b9ef7f464e40 Mon Sep 17 00:00:00 2001
From: Cliff Hansen <cwhanse@sandia.gov>
Date: Sun, 30 Sep 2018 13:20:57 -0600
Subject: [PATCH 26/33] style fixes

---
 docs/sphinx/source/api.rst             |  2 +-
 docs/sphinx/source/whatsnew/v0.6.1.rst |  4 ++--
 pvlib/test/test_solarposition.py       | 17 +++++++----------
 3 files changed, 10 insertions(+), 13 deletions(-)

diff --git a/docs/sphinx/source/api.rst b/docs/sphinx/source/api.rst
index ce28728517..c4da45ed3b 100644
--- a/docs/sphinx/source/api.rst
+++ b/docs/sphinx/source/api.rst
@@ -55,7 +55,7 @@ Additional functions for quantities closely related to solar position.
    solarposition.calc_time
    solarposition.pyephem_earthsun_distance
    solarposition.nrel_earthsun_distance
-   solarposition.get_rise_set_ephem
+   solarposition.rise_set_transit_ephem
    spa.calculate_deltat
 
 The spa module contains the implementation of the built-in NREL SPA
diff --git a/docs/sphinx/source/whatsnew/v0.6.1.rst b/docs/sphinx/source/whatsnew/v0.6.1.rst
index 8f0aefcc0d..0b6c94e3f0 100644
--- a/docs/sphinx/source/whatsnew/v0.6.1.rst
+++ b/docs/sphinx/source/whatsnew/v0.6.1.rst
@@ -12,11 +12,11 @@ date will require Python 3. (:issue:`501`)
 
 API Changes
 ~~~~~~~~~~~
-
+* Added kwarg `horizon` to :func:`~pvlib.solarposition.pyephem` and :func:`~pvlib.solarposition.calc_time` with default value `'+0:00'`
 
 Enhancements
 ~~~~~~~~~~~~
-* :func:`~pvlib.solarposition.get_rise_set_ephem` returns sunrise and sunset times using pyephem
+* :func:`~pvlib.solarposition.rise_set_transit_ephem` returns sunrise, sunset and transit times using pyephem
 
 
 Bug fixes
diff --git a/pvlib/test/test_solarposition.py b/pvlib/test/test_solarposition.py
index e83916d93c..a68c32d9bc 100644
--- a/pvlib/test/test_solarposition.py
+++ b/pvlib/test/test_solarposition.py
@@ -129,6 +129,7 @@ def test_spa_c_physical_dst(expected_solpos, golden):
     expected_solpos.index = times
     assert_frame_equal(expected_solpos, ephem_data[expected_solpos.columns])
 
+
 def test_spa_python_numpy_physical(expected_solpos, golden):
     times = pd.date_range(datetime.datetime(2003,10,17,12,30,30),
                           periods=1, freq='D', tz=golden_mst.tz)
@@ -141,6 +142,7 @@ def test_spa_python_numpy_physical(expected_solpos, golden):
     expected_solpos.index = times
     assert_frame_equal(expected_solpos, ephem_data[expected_solpos.columns])
 
+
 def test_spa_python_numpy_physical_dst(expected_solpos, golden):
     times = pd.date_range(datetime.datetime(2003,10,17,13,30,30),
                           periods=1, freq='D', tz=golden.tz)
@@ -225,14 +227,9 @@ def test_get_sun_rise_set_transit(expected_rise_set_spa, golden):
 def test_rise_set_transit_ephem(expected_rise_set_ephem, golden):
     # test for Golden, CO compare to USNO, using local midnight
     result = solarposition.rise_set_transit_ephem(
-                                              expected_rise_set_ephem.index,
-                                              golden.latitude,
-                                              golden.longitude,
-                                              next_or_previous='next',
-                                              altitude=golden.altitude,
-                                              pressure=0,
-                                              temperature=11,
-                                              horizon='-0:34')
+        expected_rise_set_ephem.index, golden.latitude, golden.longitude,
+        next_or_previous='next', altitude=golden.altitude, pressure=0,
+        temperature=11, horizon='-0:34')
     # round to nearest minute
     result_rounded = pd.DataFrame(index=result.index)
     for col, data in result.iteritems():
@@ -355,7 +352,7 @@ def test_rise_set_transit_ephem_error(expected_rise_set_ephem, golden):
 @requires_ephem
 def test_rise_set_transit_ephem_horizon(golden):
     times = pd.DatetimeIndex([datetime.datetime(2016, 1, 3, 0, 0, 0)
-                             ]).tz_localize('MST')
+                              ]).tz_localize('MST')
     # center of sun disk
     center = solarposition.rise_set_transit_ephem(times,
                                                   latitude=golden.latitude,
@@ -367,7 +364,7 @@ def test_rise_set_transit_ephem_horizon(golden):
     result_rounded = (edge['sunrise'] - center['sunrise']).dt.round('min')
 
     sunrise_delta = datetime.datetime(2016, 1, 3, 7, 17, 11) - \
-                    datetime.datetime(2016, 1, 3, 7, 21, 33)
+        datetime.datetime(2016, 1, 3, 7, 21, 33)
     expected = pd.Series(index=times,
                          data=sunrise_delta).dt.round('min')
     assert_series_equal(expected, result_rounded)

From f615f128d610048614f17ac0540368ef04aad790 Mon Sep 17 00:00:00 2001
From: Cliff Hansen <cwhanse@sandia.gov>
Date: Sun, 30 Sep 2018 14:34:16 -0600
Subject: [PATCH 27/33] Fix references to fixture golden_mst, golden

---
 pvlib/test/test_location.py      | 5 ++---
 pvlib/test/test_solarposition.py | 2 +-
 2 files changed, 3 insertions(+), 4 deletions(-)

diff --git a/pvlib/test/test_location.py b/pvlib/test/test_location.py
index b37a6cecc0..ef2b44c180 100644
--- a/pvlib/test/test_location.py
+++ b/pvlib/test/test_location.py
@@ -18,7 +18,7 @@
 import pvlib
 from pvlib.location import Location
 
-from test_solarposition import expected_solpos
+from test_solarposition import expected_solpos, golden_mst
 
 from conftest import requires_scipy
 
@@ -252,8 +252,7 @@ def test_from_tmy_2():
     assert_frame_equal(loc.tmy_data, data)
 
 
-def test_get_solarposition(expected_solpos):
-    from test_solarposition import golden_mst
+def test_get_solarposition(expected_solpos, golden_mst):
     times = pd.date_range(datetime.datetime(2003,10,17,12,30,30),
                           periods=1, freq='D', tz=golden_mst.tz)
     ephem_data = golden_mst.get_solarposition(times, temperature=11)
diff --git a/pvlib/test/test_solarposition.py b/pvlib/test/test_solarposition.py
index a68c32d9bc..87a80369b0 100644
--- a/pvlib/test/test_solarposition.py
+++ b/pvlib/test/test_solarposition.py
@@ -504,7 +504,7 @@ def test_get_solarposition_pressure(pressure, expected, golden):
 
 @pytest.mark.parametrize(
     "altitude, expected", [
-    (golden.altitude, expected_solpos()),
+    (golden().altitude, expected_solpos()),
     (2000, pd.DataFrame(
         np.array([[  39.88788,   50.11212,  194.34024,   39.87205,   14.64151,
                      50.12795]]),

From 47c95c5301d956da8163a6f3bd1e3ccf6b3093eb Mon Sep 17 00:00:00 2001
From: Cliff Hansen <cwhanse@sandia.gov>
Date: Sun, 30 Sep 2018 15:17:12 -0600
Subject: [PATCH 28/33] Add transit output to rise_set_transit_ephem

---
 pvlib/solarposition.py           |  7 ++++++-
 pvlib/test/test_solarposition.py | 10 +++++-----
 2 files changed, 11 insertions(+), 6 deletions(-)

diff --git a/pvlib/solarposition.py b/pvlib/solarposition.py
index f687dda838..faaa2cfe17 100644
--- a/pvlib/solarposition.py
+++ b/pvlib/solarposition.py
@@ -530,22 +530,27 @@ def rise_set_transit_ephem(time, latitude, longitude,
     if next_or_previous.lower() == 'next':
         rising = obs.next_rising
         setting = obs.next_setting
+        transit = obs.next_transit
     elif next_or_previous.lower() == 'previous':
         rising = obs.previous_rising
         setting = obs.previous_setting
+        transit = obs.previous_transit
     else:
         raise ValueError("next_or_previous must be either 'next' or" +
                          " 'previous'")
 
     sunrise = []
     sunset = []
+    transit = []
     for thetime in time:
         obs.date = ephem.Date(thetime)
         sunrise.append(_ephem_to_timezone(rising(sun), time.tz))
         sunset.append(_ephem_to_timezone(setting(sun), time.tz))
+        transit.append(_ephem_to_timezone(transit(sun), time.tz))
 
     return pd.DataFrame(index=time, data={'sunrise': sunrise,
-                                          'sunset': sunset})
+                                          'sunset': sunset,
+                                          'transit': transit})
 
 
 def pyephem(time, latitude, longitude, altitude=0, pressure=101325,
diff --git a/pvlib/test/test_solarposition.py b/pvlib/test/test_solarposition.py
index 87a80369b0..db3c9ec9e6 100644
--- a/pvlib/test/test_solarposition.py
+++ b/pvlib/test/test_solarposition.py
@@ -130,7 +130,7 @@ def test_spa_c_physical_dst(expected_solpos, golden):
     assert_frame_equal(expected_solpos, ephem_data[expected_solpos.columns])
 
 
-def test_spa_python_numpy_physical(expected_solpos, golden):
+def test_spa_python_numpy_physical(expected_solpos, golden_mst):
     times = pd.date_range(datetime.datetime(2003,10,17,12,30,30),
                           periods=1, freq='D', tz=golden_mst.tz)
     ephem_data = solarposition.spa_python(times, golden_mst.latitude,
@@ -503,13 +503,13 @@ def test_get_solarposition_pressure(pressure, expected, golden):
 
 
 @pytest.mark.parametrize(
-    "altitude, expected", [
-    (golden().altitude, expected_solpos()),
+    "altitude, expected",
+    [(golden().altitude, expected_solpos()),
     (2000, pd.DataFrame(
         np.array([[  39.88788,   50.11212,  194.34024,   39.87205,   14.64151,
                      50.12795]]),
-        columns=['apparent_elevation', 'apparent_zenith', 'azimuth', 'elevation',
-                 'equation_of_time', 'zenith'],
+        columns=['apparent_elevation', 'apparent_zenith', 'azimuth',
+                 'elevation', 'equation_of_time', 'zenith'],
         index=expected_solpos().index))
     ])
 def test_get_solarposition_altitude(altitude, expected, golden):

From bef44f61b9cb2da48a0aaaddcc2fccc073c79eaa Mon Sep 17 00:00:00 2001
From: Cliff Hansen <cwhanse@sandia.gov>
Date: Sun, 30 Sep 2018 15:37:33 -0600
Subject: [PATCH 29/33] Fix transit conflict

---
 pvlib/solarposition.py | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/pvlib/solarposition.py b/pvlib/solarposition.py
index faaa2cfe17..f199311b52 100644
--- a/pvlib/solarposition.py
+++ b/pvlib/solarposition.py
@@ -541,16 +541,16 @@ def rise_set_transit_ephem(time, latitude, longitude,
 
     sunrise = []
     sunset = []
-    transit = []
+    trans = []
     for thetime in time:
         obs.date = ephem.Date(thetime)
         sunrise.append(_ephem_to_timezone(rising(sun), time.tz))
         sunset.append(_ephem_to_timezone(setting(sun), time.tz))
-        transit.append(_ephem_to_timezone(transit(sun), time.tz))
+        trans.append(_ephem_to_timezone(transit(sun), time.tz))
 
     return pd.DataFrame(index=time, data={'sunrise': sunrise,
                                           'sunset': sunset,
-                                          'transit': transit})
+                                          'transit': trans})
 
 
 def pyephem(time, latitude, longitude, altitude=0, pressure=101325,

From c9b5348d4b13ca082f631382265e1e85e168cf7a Mon Sep 17 00:00:00 2001
From: Cliff Hansen <cwhanse@sandia.gov>
Date: Sun, 30 Sep 2018 15:55:07 -0600
Subject: [PATCH 30/33] Fix column order

---
 pvlib/test/test_solarposition.py | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/pvlib/test/test_solarposition.py b/pvlib/test/test_solarposition.py
index db3c9ec9e6..a724f925a9 100644
--- a/pvlib/test/test_solarposition.py
+++ b/pvlib/test/test_solarposition.py
@@ -98,9 +98,9 @@ def expected_rise_set_ephem():
                                 datetime.datetime(2015, 1, 3, 12, 5, 0),
                                 datetime.datetime(2015, 8, 2, 12, 7, 0)
                                 ]).tz_localize('MST').tolist()
-    return pd.DataFrame({'transit': transit,
-                         'sunrise': sunrise,
-                         'sunset': sunset},
+    return pd.DataFrame({'sunrise': sunrise,
+                         'sunset': sunset,
+                         'transit': transit},
                         index=times)
 # the physical tests are run at the same time as the NREL SPA test.
 # pyephem reproduces the NREL result to 2 decimal places.

From 92e0677ab4b5bf9da07d68a6d342e0748ea564fb Mon Sep 17 00:00:00 2001
From: Cliff Hansen <cwhanse@sandia.gov>
Date: Sun, 30 Sep 2018 16:20:19 -0600
Subject: [PATCH 31/33] Minor test adjustments

---
 pvlib/test/test_solarposition.py | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/pvlib/test/test_solarposition.py b/pvlib/test/test_solarposition.py
index a724f925a9..64d244cc29 100644
--- a/pvlib/test/test_solarposition.py
+++ b/pvlib/test/test_solarposition.py
@@ -91,7 +91,7 @@ def expected_rise_set_ephem():
     sunset = pd.DatetimeIndex([datetime.datetime(2015, 1, 1, 16, 47, 0),
                                datetime.datetime(2015, 1, 2, 16, 48, 0),
                                datetime.datetime(2015, 1, 3, 16, 49, 0),
-                               datetime.datetime(2015, 8, 2, 19, 13, 0)
+                               datetime.datetime(2015, 8, 2, 19, 14, 0)
                                ]).tz_localize('MST').tolist()
     transit = pd.DatetimeIndex([datetime.datetime(2015, 1, 1, 12, 4, 0),
                                 datetime.datetime(2015, 1, 2, 12, 5, 0),
@@ -366,7 +366,8 @@ def test_rise_set_transit_ephem_horizon(golden):
     sunrise_delta = datetime.datetime(2016, 1, 3, 7, 17, 11) - \
         datetime.datetime(2016, 1, 3, 7, 21, 33)
     expected = pd.Series(index=times,
-                         data=sunrise_delta).dt.round('min')
+                         data=sunrise_delta,
+                         name='sunrise').dt.round('min')
     assert_series_equal(expected, result_rounded)
 
 

From db08f8dbbef83a99835a355b8ff37567a961ec36 Mon Sep 17 00:00:00 2001
From: Cliff Hansen <cwhanse@sandia.gov>
Date: Mon, 1 Oct 2018 08:39:46 -0600
Subject: [PATCH 32/33] Add handling of utcoffset

---
 pvlib/solarposition.py           | 3 ++-
 pvlib/test/test_solarposition.py | 2 +-
 2 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/pvlib/solarposition.py b/pvlib/solarposition.py
index f199311b52..c68c44f80c 100644
--- a/pvlib/solarposition.py
+++ b/pvlib/solarposition.py
@@ -543,7 +543,8 @@ def rise_set_transit_ephem(time, latitude, longitude,
     sunset = []
     trans = []
     for thetime in time:
-        obs.date = ephem.Date(thetime)
+        thetime = thetime.to_pydatetime()
+        obs.date = ephem.Date(thetime - thetime.utcoffset())
         sunrise.append(_ephem_to_timezone(rising(sun), time.tz))
         sunset.append(_ephem_to_timezone(setting(sun), time.tz))
         trans.append(_ephem_to_timezone(transit(sun), time.tz))
diff --git a/pvlib/test/test_solarposition.py b/pvlib/test/test_solarposition.py
index 64d244cc29..6c407a7a9b 100644
--- a/pvlib/test/test_solarposition.py
+++ b/pvlib/test/test_solarposition.py
@@ -91,7 +91,7 @@ def expected_rise_set_ephem():
     sunset = pd.DatetimeIndex([datetime.datetime(2015, 1, 1, 16, 47, 0),
                                datetime.datetime(2015, 1, 2, 16, 48, 0),
                                datetime.datetime(2015, 1, 3, 16, 49, 0),
-                               datetime.datetime(2015, 8, 2, 19, 14, 0)
+                               datetime.datetime(2015, 8, 2, 19, 13, 0)
                                ]).tz_localize('MST').tolist()
     transit = pd.DatetimeIndex([datetime.datetime(2015, 1, 1, 12, 4, 0),
                                 datetime.datetime(2015, 1, 2, 12, 5, 0),

From c05bae7e4e1cfa93174589f3270c36a533b161b5 Mon Sep 17 00:00:00 2001
From: Cliff Hansen <cwhanse@sandia.gov>
Date: Mon, 1 Oct 2018 08:51:53 -0600
Subject: [PATCH 33/33] Inline comment

---
 pvlib/solarposition.py | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/pvlib/solarposition.py b/pvlib/solarposition.py
index c68c44f80c..b8b2e20274 100644
--- a/pvlib/solarposition.py
+++ b/pvlib/solarposition.py
@@ -544,6 +544,8 @@ def rise_set_transit_ephem(time, latitude, longitude,
     trans = []
     for thetime in time:
         thetime = thetime.to_pydatetime()
+        # pyephem drops timezone when converting to its internal datetime
+        # format, so handle timezone explicitly here
         obs.date = ephem.Date(thetime - thetime.utcoffset())
         sunrise.append(_ephem_to_timezone(rising(sun), time.tz))
         sunset.append(_ephem_to_timezone(setting(sun), time.tz))