def test_polar():
z = 1 + 1j
mag, arg = _u.complex_to_polar(z)
assert is_zero(mag - sqrt(2), tolerance=1e-10)
assert is_zero(arg - pi / 4, tolerance=1e-10)
#
# Then arrays
#
z = array([[1, 2], [3, 4]]) + array([[4, 3], [2, 1]]) * 1j
mag, arg = _u.complex_to_polar(z)
assert arrays_equal(mag - abs(z), 0, tolerance=1e-10)
assert arrays_equal(arg - log(z).imag, 0, tolerance=1e-10)
#
# Then do the opposite
#
assert is_zero(1 + 1j - _u.polar_to_complex(sqrt(2), pi / 4), tolerance=1e-10)
#
# Make phase "continuous":
#
x = _u.linspace(0, 10, 20) * pi
y = array(x, copy=True)
y[3] -= 1 * 2 * pi
y[9] -= 6 * 2 * pi
y[12] += 1 * 2 * pi
z = _u.continuous_phase(y)
assert arrays_equal(x, z, tolerance=1e-10)
#
# Also, "center" the phase:
#
z = _u.continuous_phase(y, center=True)
assert max(abs(z)) <= 6.000001 * pi
assert arrays_equal(exp(1j * z), exp(1j * x), tolerance=1e-10)
assert arrays_equal(exp(1j * y), exp(1j * x), tolerance=1e-10)
#
# Then the same, but along a different axis
#
x = _u.stretch_shape(_u.linspace(0, 10, 20) * pi, (5, 6, -1))
y = array(x, copy=True)
y[:, :, 3] -= 2 * 2 * pi
y[:, :, 2] -= 1 * 2 * pi
y[:, :, 5] += 3 * 2 * pi
z = _u.continuous_phase(y, axis=2)
assert arrays_equal(x, z, tolerance=1e-10)
def test_linspace():
assert arrays_equal(_u.linspace(0, 1, 29), scipy.linspace(0, 1, 29))
