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from pystencils import Assignment, create_kernel
from pystencils.boundaries import BoundaryHandling, Neumann, add_neumann_boundary
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from pystencils.datahandling import SerialDataHandling
from pystencils.slicing import slice_from_direction
def test_kernel_vs_copy_boundary():
dh = SerialDataHandling(domain_size=(7, 7))
src = dh.add_array('src')
dst_builtin = dh.add_array_like('dst_builtin', 'src')
dst_python_copy = dh.add_array_like('dst_python_copy', 'src')
dst_handling = dh.add_array_like('dst_handling', 'src')
src_arr = np.arange(dh.shape[0] * dh.shape[1]).reshape(dh.shape)
def reset_src():
for block in dh.iterate(ghost_layers=True, inner_ghost_layers=True):
np.copyto(block['src'], np.random.rand(*block.shape))
for block in dh.iterate(ghost_layers=False, inner_ghost_layers=True):
np.copyto(block['src'], src_arr)
for b in dh.iterate(ghost_layers=False, inner_ghost_layers=True):
np.copyto(b['dst_builtin'], 42)
np.copyto(b['dst_python_copy'], 43)
np.copyto(b['dst_handling'], 44)
flags = dh.add_array('flags', dtype=np.uint8)
dh.fill(flags.name, 0)
borders = ['N', 'S', 'E', 'W']
for d in borders:
dh.fill(flags.name, 1, slice_obj=slice_from_direction(d, dim=2), ghost_layers=True, inner_ghost_layers=True)
rhs = sum(src.neighbors([(1, 0), (-1, 0), (0, 1), (0, -1)]))
simple_kernel = create_kernel([Assignment(dst_python_copy.center, rhs)]).compile()
kernel_handling = create_kernel([Assignment(dst_handling.center, rhs)]).compile()
assignments_with_boundary = add_neumann_boundary([Assignment(dst_builtin.center, rhs)],
fields=[src], flag_field=flags, boundary_flag=1)
kernel_with_boundary = create_kernel(assignments_with_boundary).compile()
# ------ Method 1: Built-in boundary
reset_src()
dh.run_kernel(kernel_with_boundary)
# ------ Method 2: Using python to copy out the values (reference)
reset_src()
for b in dh.iterate():
arr = b['src']
arr[:, 0] = arr[:, 1]
arr[:, -1] = arr[:, -2]
arr[0, :] = arr[1, :]
arr[-1, :] = arr[-2, :]
dh.run_kernel(simple_kernel)
# ------ Method 3: Using boundary handling to copy out the values
reset_src()
boundary_stencil = [(1, 0), (-1, 0), (0, 1), (0, -1)]
boundary_handling = BoundaryHandling(dh, src.name, boundary_stencil)
neumann = Neumann()
assert neumann.name == 'Neumann'
neumann.name = "wall"
assert neumann.name == 'wall'
assert neumann.additional_data_init_callback is None
assert len(neumann.additional_data) == 0
for d in ('N', 'S', 'W', 'E'):
boundary_handling.set_boundary(neumann, slice_from_direction(d, dim=2))
boundary_handling()
dh.run_kernel(kernel_handling)
python_copy_result = dh.gather_array('dst_python_copy')
builtin_result = dh.gather_array('dst_builtin')
handling_result = dh.gather_array('dst_handling')
np.testing.assert_almost_equal(python_copy_result, builtin_result)
np.testing.assert_almost_equal(python_copy_result, handling_result)
with TemporaryDirectory() as tmp_dir:
boundary_handling.geometry_to_vtk(file_name=os.path.join(tmp_dir, 'test_output1'), ghost_layers=False)
boundary_handling.geometry_to_vtk(file_name=os.path.join(tmp_dir, 'test_output2'), ghost_layers=True)