def test_as_coordinate_map():
ijk = CoordinateSystem('ijk')
xyz = CoordinateSystem('xyz')
A = np.random.standard_normal((4,4))
# bottom row of A is not [0,0,0,1]
yield assert_raises, ValueError, AffineTransform, ijk, xyz, A
A[-1] = [0,0,0,1]
aff = AffineTransform(ijk, xyz, A)
_cmapA = _as_coordinate_map(aff)
yield assert_true, isinstance(_cmapA, CoordinateMap)
yield assert_true, _cmapA.inverse_function != None
# a non-invertible one
B = A[1:]
xy = CoordinateSystem('xy')
affB = AffineTransform(ijk, xy, B)
_cmapB = _as_coordinate_map(affB)
yield assert_true, isinstance(_cmapB, CoordinateMap)
yield assert_true, _cmapB.inverse_function == None
def test_shift_origin():
CS = CoordinateSystem
A = np.random.standard_normal((5,6))
A[-1] = [0,0,0,0,0,1]
aff1 = AffineTransform(CS('ijklm', 'oldorigin'), CS('xyzt'), A)
difference = np.random.standard_normal(5)
point_in_old_basis = np.random.standard_normal(5)
for aff in [aff1, _as_coordinate_map(aff1)]:
# The same affine transforation with a different origin for its domain
shifted_aff = shifted_domain_origin(aff, difference, 'neworigin')
# This is the relation ship between coordinates in old and new origins
yield assert_true, np.allclose(shifted_aff(point_in_old_basis), aff(point_in_old_basis+difference))
yield assert_true, np.allclose(shifted_aff(point_in_old_basis-difference), aff(point_in_old_basis))
# OK, now for the range
A = np.random.standard_normal((5,6))
A[-1] = [0,0,0,0,0,1]
aff2 = AffineTransform(CS('ijklm', 'oldorigin'), CS('xyzt'), A)
difference = np.random.standard_normal(4)
for aff in [aff2, _as_coordinate_map(aff2)]:
# The same affine transforation with a different origin for its domain
shifted_aff = shifted_range_origin(aff, difference, 'neworigin')
# Let's check that things work
point_in_old_basis = np.random.standard_normal(5)
# This is the relation ship between coordinates in old and new origins
yield assert_true, np.allclose(shifted_aff(point_in_old_basis), aff(point_in_old_basis)-difference)
yield assert_true, np.allclose(shifted_aff(point_in_old_basis)+difference, aff(point_in_old_basis))
