def test_trivial_weight_function_case(xy_vectors):
""" If weights are [1,1,1,1] the result should be the same as weights=None"""
weights = [1, 1, 1, 1]
four_vectors = np.asarray([[1, 0, 1, 1], [0, 1, -1, 1]])
deformed = hs.signals.Signal2D(generate_test_vectors(four_vectors))
weight_strain_map = get_DisplacementGradientMap(deformed, four_vectors, weights=weights).get_strain_maps()
np.testing.assert_almost_equal(xy_vectors.data, weight_strain_map.data, decimal=2)
def test_weight_function_behaviour():
""" Confirms that a weight function [1,1,2,2] on [a,a,b,b] gives (2a+4b)/6 as the strain"""
multi_vector_array = np.asarray([[1, 0, 1, 1], [0, 1, -1, 1]])
strained_by_1pc_in_x = vector_operation(multi_vector_array, np.asarray([[1.01, 0], [0, 1]])) # first 2
strained_by_2pc_in_x = vector_operation(multi_vector_array, np.asarray([[1.02, 0], [0, 1]])) # second 2
weights = [1, 1, 2, 2] # ((0.1*2 + 0.2*4)/6) = 0.166666
vectors = np.concatenate((strained_by_1pc_in_x[:, :2], strained_by_2pc_in_x[:, 2:]), axis=1)
deformed = hs.signals.Signal2D(np.asarray([[vectors, vectors], [vectors, vectors]]))
strain_map = get_DisplacementGradientMap(deformed, multi_vector_array, weights=weights).get_strain_maps()
np.testing.assert_almost_equal(strain_map.inav[0].isig[0, 0].data[0], -1.0166666 + 1, decimal=2)
def generate_strain_map(vectors):
dp = hs.signals.Signal2D(generate_test_vectors(vectors))
st = get_DisplacementGradientMap(dp, vectors).get_strain_maps()
return st
def Displacement_Grad_Map():
xy = np.asarray([[1, 0], [0, 1]])
deformed = hs.signals.Signal2D(generate_test_vectors(xy))
D = get_DisplacementGradientMap(deformed, xy)
return D
def generate_strain_map(vectors):
deformed = hs.signals.Signal2D(generate_test_vectors(vectors))
return get_DisplacementGradientMap(deformed, vectors).get_strain_maps()