add some tests functions

diffpy/labpdfproc/functions.py

@@ -129,7 +129,7 @@ def _get_entry_exit_coordinates(self, coordinate, angle):
             xexit_root1, xexit_root2 = np.roots((1 + a**2, 2 * a * b, b**2 - self.radius**2))
             yexit_root1 = a * xexit_root1 + b
             yexit_root2 = a * xexit_root2 + b
-            if yexit_root2 >= ygrid:  # We pick the point above
+            if yexit_root2 >= yexit_root1:  # We pick the point above
                 exit_point = (xexit_root2, yexit_root2)
             else:
                 exit_point = (xexit_root1, yexit_root1)

diffpy/labpdfproc/tests/test_get_grid_points.py

@@ -0,0 +1,38 @@
+import numpy as np
+import pytest
+
+from diffpy.labpdfproc.functions import Gridded_circle
+
+
+def test_get_grid_points():
+    actual_gs = Gridded_circle(radius=1, n_points_on_diameter=3, mu=1)
+    expected_gs = Gridded_circle()
+    expected_gs.grid = {(0.0, -1.0), (0.0, 0.0), (-1.0, 0.0), (1.0, 0.0), (0.0, 1.0)}
+    expected_gs.total_points_in_grid = 5
+    assert actual_gs.grid == expected_gs.grid
+    assert actual_gs.total_points_in_grid == expected_gs.total_points_in_grid
+
+
+"""
+class TestGetGridPoints:
+    def setUp(self):
+        self.radius = 5
+        self.npoints = 10
+        self._get_grid_points()
+
+        #
+        self.radius = 0.5
+        self.grid = [(-0.026315789473684237, -0.4473684210526316),
+                     (0.13157894736842102, -0.2368421052631579),
+                     (0.18421052631578938, 0.02631578947368418),
+                     (0.3421052631578947, 0.18421052631578938),
+                     (0.02631578947368418, -0.4473684210526316),
+                     (0.18421052631578938, -0.2368421052631579),
+                     (0.2894736842105263, 0.07894736842105265),
+                     (0.2894736842105263, 0.18421052631578938),
+                     (-0.1842105263157895, -0.39473684210526316),
+                     (0.23684210526315785, -0.2368421052631579),
+                     (-0.2368421052631579, 0.07894736842105265),
+                     (0.23684210526315785, 0.18421052631578938)]
+        #self.total_points_in_grid = len(self.grid)
+"""

diffpy/labpdfproc/tests/test_set_distances_at_angle.py

@@ -0,0 +1,23 @@
+import pytest
+
+from diffpy.labpdfproc.functions import Gridded_circle
+
+
+def test_set_distances_at_angle():
+    actual_gs = Gridded_circle(radius=1, n_points_on_diameter=3, mu=1)
+
+    # tests for acute angles
+    actual_gs.set_distances_at_angle(25)
+    actual_acute = actual_gs.distances
+    expected_acute = [0, 2, 1.81261557406, 2, 0.845236523481399]
+    assert actual_acute == pytest.approx(expected_acute, rel=1e-4, abs=1e-6)
+
+    actual_gs.set_distances_at_angle(90)
+    actual_right = actual_gs.distances
+    expected_right = [0, 2, 0, 2, 2]
+    assert actual_right == pytest.approx(expected_right, rel=1e-4, abs=1e-6)
+
+    actual_gs.set_distances_at_angle(140)
+    actual_obtuse = actual_gs.distances
+    expected_obtuse = [0, 2, 0, 3.5320888862379562, 1.2855752193730785]
+    assert actual_obtuse == pytest.approx(expected_obtuse, rel=1e-4, abs=1e-6)