Added test for SimplexSpline.__call__ using both cartesian and

barycentric coordinates. Made a modification to __call__
in order to support evaluation at single points.

SSplines/simplex_spline.py

@@ -2,7 +2,7 @@
 
 from SSplines.dicts import KNOT_CONFIGURATION_TO_FACE_INDICES
 from SSplines.helper_functions import barycentric_coordinates, determine_sub_triangle, \
-    points_from_barycentric_coordinates
+    points_from_barycentric_coordinates, simplex_spline_graphic_small
 from SSplines.symbolic import polynomial_pieces
 
 
@@ -40,3 +40,9 @@ def __call__(self, y, exact=False, barycentric=False):
         else:
             return np.array([self.polynomial_pieces[k[i]].subs({'X': x[i][0], 'Y': x[i][1]}) for i in range(len(x))],
                             dtype=np.float)
+
+    def display(self):
+        """
+        Displays the SimplexSpline using graphical notation.
+        """
+        simplex_spline_graphic_small(self.knot_multiplicities)

tests/test_exact_arithmetic.py

@@ -0,0 +1,18 @@
+import numpy as np
+
+from SSplines import barycentric_coordinates
+
+
+def test_barycentric_coordinates():
+    triangle = np.array([
+        [0, 0],
+        [1, 0],
+        [0, 1]
+    ])
+    x = np.array([0.5, 0.5])
+
+    b_numerical = barycentric_coordinates(triangle, x, exact=False)
+    b_exact = barycentric_coordinates(triangle, x, exact=True)
+
+    for num, exac in zip(b_numerical, b_exact):
+        np.testing.assert_almost_equal(num, exac)