add basic tests, and test of preprocessing. Testing the other options…

…/functionality will be more difficult.

deltametrics/plan.py

@@ -1700,7 +1700,7 @@ def shaw_opening_angle_method(
         Binary image that has been thresholded to split water/land. At
         minimum, this should be a thresholded elevation matrix, or some
         classification of land/water based on pixel color or reflectance
-        intensity. This is the startin point (i.e., guess) for the opening
+        intensity. This is the starting point for the opening
         angle method.
 
     numviews : int, optional
@@ -1748,12 +1748,15 @@ def shaw_opening_angle_method(
     #   set refers to the points which bound the angle calculations.
 
     ## Preprocess
-    #   Preprocess in orginal paper: "we pre-process by filling lakes
-    #   (contiguous sets of water pixels surrounded by land)"
     if preprocess:
+        # Preprocess in orginal paper: "we pre-process by filling lakes
+        #   (contiguous sets of water pixels surrounded by land)"
         below_mask = np.logical_not(
             binary_fill_holes(np.logical_not(below_mask))
         ).astype(int)
+    else:
+        # Ensure array is integer binary
+        below_mask = below_mask.astype(int)
 
     ## Find land-water interface (`edges`)
     # find the edges of the below_mask by a gradient approach in x and y

tests/test_plan.py

@@ -329,12 +329,30 @@ def test_bad_type(self):
 
 
 class TestShawOpeningAngleMethod:
-    simple_ocean = 1 - simple_land
-
-    # NEED TESTS
+    simple_ocean = 1 - simple_land  # ocean is at bottom of image
 
-    def test_null(self):
-        pass
+    def test_allblack(self):
+        with pytest.raises(ValueError, match=r"No pixels identified in below_mask.*"):
+            _ = plan.shaw_opening_angle_method(np.zeros((10, 10), dtype=int))
+
+    def test_simple_case_defaults(self):
+        oam = plan.shaw_opening_angle_method(self.simple_ocean)
+        assert np.all(oam <= 180)
+        assert np.all(oam >= 0)
+        assert np.all(oam[-1, :] == 180)
+
+    def test_simple_case_preprocess(self):
+        # make a custom mask with a lake
+        _custom_ocean = np.copy(self.simple_ocean)
+        _custom_ocean[1:3, 1:3] = 1  # add a lake
+
+        # the lake should be removed (default)
+        oam1 = plan.shaw_opening_angle_method(_custom_ocean, preprocess=True)
+        assert np.all(oam1[1:3, 1:3] == 0)
+
+        # the lake should persist
+        oam2 = plan.shaw_opening_angle_method(_custom_ocean, preprocess=False)
+        assert np.all(oam2[1:3, 1:3] != 0)
 
 
 class TestDeltaArea: