def testEdgeNormal(self):
a = Node((0,0),(0,0))
b = Node((1,0),(0,0))
c = Node((0,1),(0,0))
t = Triangle(a, b, c)
xaxisedge = t.edges[0]
reversedxaxisedge = Edge(xaxisedge.nodes[1], xaxisedge.nodes[0])
diagonaledge = t.edges[1]
yaxisedge = t.edges[2]
self.assertTrue((xaxisedge.getNormal(t) == (0, -1)).all())
self.assertTrue((reversedxaxisedge.getNormal(t) == (0, -1)).all())
self.assertTrue((yaxisedge.getNormal(t) == (-1, 0)).all())
self.assertTrue((diagonaledge.getNormal(t) == (1/sqrt(2), 1/sqrt(2))).all())
