Merge pull request #47 from Freeman-Trader/easy-annotation

Add Easy Annotations

ridge_map/ridge_map.py

@@ -78,6 +78,7 @@ def __init__(self, bbox=(-71.928864, 43.758201, -70.957947, 44.465151), font=Non
         if font is None:
             font = FontManager().prop
         self.font = font
+        self.annotations = list()
 
     @property
     def lats(self):
@@ -161,6 +162,51 @@ def preprocess(
         values[np.logical_or(is_water, is_lake)] = np.nan
         values = vertical_ratio * values[-1::-1]  # switch north and south
         return values
+
+    def add_annotation(
+        self, 
+        label="Mount Washington", 
+        coordinates=(-71.3173, 44.2946), 
+        x_offset=-0.25, 
+        y_offset=-0.045, 
+        label_size=30,
+        annotation_size=8,
+        color=None, 
+        background=True
+    ):
+        """Save an annotation.
+
+        Must call before plot_map()
+
+        Parameters
+        ----------
+        label : string
+            Label to place on the map. Use an empty string for no label.
+        coordinates : (float, float)
+            The coordinates of the annotation as Longitude, Latitude
+        x_offset : float
+            Where to position the label relative to the annotation horizontally
+        y_offset : float
+            Where to position the label relative to the annotation vertically
+        label_size : int
+            fontsize of the label
+        annotation_size : int
+            Size of the annotation marking
+        label_color : string or None
+            Color for the label. If None, then uses label_color of map
+        background : bool
+            If there is a background or not
+        """
+        self.annotations.append((
+            label,
+            coordinates,
+            x_offset, 
+            y_offset, 
+            label_size, 
+            annotation_size, 
+            color, 
+            background
+        ))
 
     # pylint: disable=too-many-arguments,too-many-locals
     def plot_map(
@@ -219,6 +265,39 @@ def plot_map(
         -------
         matplotlib.Axes
         """
+        def plot_annotations():
+            """Plot the annotations.
+
+            Takes all the annotations from self.annotations and adds them to the map    
+            """
+            for annotation in self.annotations:
+                rel_coordinates = ((annotation[1][0] - self.longs[0])/(self.longs[1] - self.longs[0]),(annotation[1][1] - self.lats[0])/(self.lats[1] - self.lats[0]))
+                annotation_color = ax.texts[0].get_color()
+                if annotation[6] is not None:
+                    annotation_color = annotation[6]
+
+                ax.text(
+                    rel_coordinates[0] + annotation[2],
+                    rel_coordinates[1] + annotation[3],
+                    annotation[0],
+                    fontproperties=self.font,
+                    size=annotation[4],
+                    color=annotation_color,
+                    transform=ax.transAxes,
+                    bbox={"facecolor": background_color, "alpha": 1, "linewidth": 1} if annotation[7] else None,
+                    verticalalignment="bottom",
+                    zorder=len(values) + 10
+                )
+
+                ax.plot(
+                    *rel_coordinates, 
+                    'o', 
+                    color=annotation_color,
+                    transform=ax.transAxes,
+                    ms=annotation[5],
+                    zorder=len(values) + 10
+                )
+
         if kind not in {"gradient", "elevation"}:
             raise TypeError("Argument `kind` must be one of 'gradient' or 'elevation'")
         if values is None:
@@ -275,4 +354,7 @@ def plot_map(
         for spine in ax.spines.values():
             spine.set_visible(False)
         ax.set_facecolor(background_color)
+
+        plot_annotations()
+
         return ax