refactor: allow solve_fe docs without sfepy

Allow solve_fe to display its documentation without having to import
sfepy.

pymks/__init__.py

@@ -26,20 +26,8 @@
 from .fmks.correlations import TwoPointCorrelation
 from .fmks.data.checkerboard import generate_checkerboard
 from .fmks.pair_correlations import paircorr_from_twopoint
+from .fmks.data import solve_fe
 
-try:
-    import sfepy  # noqa: F401
-except ImportError:
-
-    def solve_fe(*_, **__):
-        """Dummy funcion when sfepy unavailable
-        """
-        # pylint: disable=redefined-outer-name, import-outside-toplevel, unused-import
-        import sfepy  # noqa: F401, F811
-
-
-else:
-    from .fmks.data.elastic_fe import solve_fe
 
 # the following will be deprecated
 from .mks_localization_model import MKSLocalizationModel
@@ -51,7 +39,7 @@ def solve_fe(*_, **__):
 MKSRegressionModel = MKSLocalizationModel
 DiscreteIndicatorBasis = PrimitiveBasis
 ContinuousIndicatorBasis = PrimitiveBasis
-# the above will be deprecatec
+# the above will be deprecated
 
 
 def test():

pymks/fmks/data/__init__.py

@@ -0,0 +1,31 @@
+"""Functions for generating data
+"""
+from ..func import curry
+
+
+@curry
+def solve_fe(x_data, elastic_modulus, poissons_ratio, macro_strain=1.0, delta_x=1.0):
+    """Solve the elasticity problem
+
+    Args:
+      x_data: microstructure with shape (n_samples, n_x, ...)
+      elastic_modulus: the elastic modulus in each phase
+      poissons_ration: the poissons ratio for each phase
+      macro_strain: the macro strain
+      delta_x: the grid spacing
+
+    Returns:
+      a dictionary of strain, displacement and stress with stress and
+      strain of shape (n_samples, n_x, ..., 3) and displacement shape
+      of (n_samples, n_x + 1, ..., 2)
+
+    """
+    from .elastic_fe import _solve_fe  # pylint: disable=import-outside-toplevel
+
+    return _solve_fe(
+        x_data,
+        elastic_modulus,
+        poissons_ratio,
+        macro_strain=macro_strain,
+        delta_x=delta_x,
+    )

pymks/fmks/data/elastic_fe.py

@@ -12,7 +12,7 @@
 >>> X = np.zeros((1, 3, 3), dtype=int)
 >>> X[0, :, 1] = 1
 
->>> strain = solve_fe(
+>>> strain = _solve_fe(
 ...     X,
 ...     elastic_modulus=(1.0, 10.0),
 ...     poissons_ratio=(0., 0.),
@@ -43,7 +43,7 @@
 ...                [1, 0, 0, 1]]])
 >>> n_samples, N, N = X.shape
 >>> macro_strain = 0.1
->>> displacement = solve_fe(
+>>> displacement = _solve_fe(
 ...     X,
 ...     elastic_modulus=(10.0, 1.0),
 ...     poissons_ratio=(0.3, 0.3),
@@ -80,7 +80,7 @@
 >>> print(X.shape)
 (2, 4, 4)
 >>> x_data = da.from_array(X, chunks=(1, 4, 4))
->>> out = solve_fe(x_data,
+>>> out = _solve_fe(x_data,
 ...             elastic_modulus=(10.0, 1.0),
 ...             poissons_ratio=(0.3, 0.3),
 ...             macro_strain=macro_strain)['displacement']
@@ -145,23 +145,7 @@
 
 
 @curry
-def solve_fe(x_data, elastic_modulus, poissons_ratio, macro_strain=1.0, delta_x=1.0):
-    """Solve the elasticity problem
-
-    Args:
-      x_data: microstructure with shape (n_samples, n_x, ...)
-      elastic_modulus: the elastic modulus in each phase
-      poissons_ration: the poissons ratio for each phase
-      macro_strain: the macro strain
-      delta_x: the grid spacing
-
-    Returns:
-      a dictionary of strain, displacement and stress with stress and
-      strain of shape (n_samples, n_x, ..., 3) and displacement shape
-      of (n_samples, n_x + 1, ..., 2)
-
-    """
-
+def _solve_fe(x_data, elastic_modulus, poissons_ratio, macro_strain=1.0, delta_x=1.0):
     def solve_one_sample(property_array):
         return pipe(
             get_fields(property_array.shape[:-1], delta_x),

pymks/fmks/tests/test_fe.py

@@ -4,7 +4,7 @@
 import pytest
 import numpy as np
 from toolz.curried import pipe, first, get
-from pymks.fmks.data.elastic_fe import solve_fe
+from pymks.fmks.data import solve_fe
 
 
 def test_3d():

pymks/fmks/tests/test_localization.py

@@ -9,7 +9,7 @@
 from pymks.fmks.bases.primitive import PrimitiveTransformer
 from pymks.fmks.localization import LocalizationRegressor
 from pymks.fmks.data.delta import generate_delta
-from pymks.fmks.data.elastic_fe import solve_fe
+from pymks.fmks.data import solve_fe
 
 
 def _get_x():