def test_normal_identical_vertices(self):
     plane = array([[ 166.585,  918.653,  935.901], [ 166.585,  918.653,  935.901], [ 137.632,  619.804,   83.351]])
     self.assertTrue((normcore.normal(plane) == array([0.0, 0.0, 0.0])).all(), msg = "Non-zero normal vector unexpectedly returned for plane with duplicate vertices.")
 def test_normal(self):
     plane = array([[ 166.585,  918.653,  935.901], [ 611.921,  676.73 ,  417.434], [ 137.632,  619.804,   83.351]])
     self.assertTrue(allclose(normcore.normal(plane), array([51308.109167, 394682.381851, -140092.614883])), msg = "Normal vector not calculated as expected.")