def test_gradient_cuda():
"""Discretized spatial gradient operator using CUDA."""
# DiscreteLp Vector
discr_space = odl.uniform_discr([0, 0], [6, 2.5], DATA_2D.shape,
impl='cuda')
dom_vec = discr_space.element(DATA_2D)
# computation of gradient components with helper function
dx0, dx1 = discr_space.cell_sides
diff_0 = finite_diff(DATA_2D, axis=0, dx=dx0, padding_method='constant')
diff_1 = finite_diff(DATA_2D, axis=1, dx=dx1, padding_method='constant')
# gradient
grad = Gradient(discr_space)
grad_vec = grad(dom_vec)
assert len(grad_vec) == DATA_2D.ndim
assert all_equal(grad_vec[0].asarray(), diff_0)
assert all_equal(grad_vec[1].asarray(), diff_1)
# adjoint operator
ran_vec = grad.range.element([DATA_2D, DATA_2D ** 2])
adj_vec = grad.adjoint(ran_vec)
lhs = ran_vec.inner(grad_vec)
rhs = dom_vec.inner(adj_vec)
assert lhs != 0
assert rhs != 0
assert lhs == rhs
def test_gradient_cpu():
"""Discretized spatial gradient operator."""
with pytest.raises(TypeError):
Gradient(odl.Rn(1))
# DiscreteLp Vector
discr_space = odl.uniform_discr([0, 0], [6, 2.5], DATA_2D.shape)
dom_vec = discr_space.element(DATA_2D)
# computation of gradient components with helper function
dx0, dx1 = discr_space.cell_sides
diff_0 = finite_diff(DATA_2D, axis=0, dx=dx0, method='forward',
padding_method='constant')
diff_1 = finite_diff(DATA_2D, axis=1, dx=dx1, method='forward',
padding_method='constant')
# gradient
grad = Gradient(discr_space)
grad_vec = grad(dom_vec)
assert len(grad_vec) == DATA_2D.ndim
assert all_equal(grad_vec[0].asarray(), diff_0)
assert all_equal(grad_vec[1].asarray(), diff_1)
# Test adjoint operator
ran_vec = grad.range.element([DATA_2D, DATA_2D ** 2])
adj_vec = grad.adjoint(ran_vec)
lhs = ran_vec.inner(grad_vec)
rhs = dom_vec.inner(adj_vec)
# Check not to use trivial data
assert lhs != 0
assert rhs != 0
assert lhs == rhs
# higher dimensional arrays
lin_size = 3
for ndim in range(1, 6):
# DiscreteLp Vector
discr_space = odl.uniform_discr([0.] * ndim, [lin_size] * ndim,
[lin_size] * ndim)
dom_vec = discr_space.element(ndvolume(lin_size, ndim))
# gradient
grad = Gradient(discr_space)
grad(dom_vec)