def center_of_mass(vertices):
"""
Return center of mass of polygon spanned by vertex list.
Parameters
----------
vertices : N x 2 np.ndarray
Returns
-------
center : 1 x 2 np.ndarray
"""
center = np.array([0, 0], dtype='float')
area = find_area_of_polygon(vertices)
decomposition = decompose_to_triangles(vertices)
for triangle in decomposition:
area_of_triangle = find_area_of_polygon(triangle)
center_of_triangle = find_center_of_mass_triangle(triangle)
center += area_of_triangle*center_of_triangle
center = (1/area)*center
return center
def test_area_pentagon(self):
# Make sure area is correct for pentagon.
self.assertEqual(find_area_of_polygon(self.pentagon), 3.5)
def test_area_trapezoid(self):
# Make sure area is correct for trapezoid.
self.assertEqual(find_area_of_polygon(self.trapezoid), 1.5)
def test_area_square(self):
# Make sure area is correct for square.
self.assertEqual(find_area_of_polygon(self.square), 1.0)
def test_area_triangle2(self):
# Make sure area is correct for another triangle.
self.assertEqual(find_area_of_polygon(self.triangle2), 1.0)
def test_area_triangle1(self):
# Make sure area is correct for triangle.
self.assertEqual(find_area_of_polygon(self.triangle1), 0.5)
