def test_mistmatched_mesh():
"""
Test the calling of :func:`esmf_regrid.experimental.unstructured_scheme.MeshToGridESMFRegridder`.
Checks that an error is raised when the regridder is called with a cube
whose mesh does not match the one used for initialisation.
"""
n_lons = 6
n_lats = 5
lon_bounds = (-180, 180)
lat_bounds = (-90, 90)
tgt = _grid_cube(n_lons, n_lats, lon_bounds, lat_bounds, circular=True)
src = _gridlike_mesh_cube(n_lons, n_lats)
other_loc = _gridlike_mesh_cube(n_lons, n_lats, location="node")
other_src = _flat_mesh_cube()
rg = MeshToGridESMFRegridder(src, tgt)
with pytest.raises(ValueError) as excinfo:
_ = rg(tgt)
expected_message = "The given cube is not defined on a mesh."
assert expected_message in str(excinfo.value)
with pytest.raises(ValueError) as excinfo:
_ = rg(other_loc)
expected_message = ("The given cube is not defined on a the same "
"mesh location as this regridder.")
assert expected_message in str(excinfo.value)
with pytest.raises(ValueError) as excinfo:
_ = rg(other_src)
expected_message = (
"The given cube is not defined on the same source mesh as this regridder."
)
assert expected_message in str(excinfo.value)
def test_invalid_method():
"""
Test initialisation of :func:`esmf_regrid.experimental.unstructured_scheme.MeshToGridESMFRegridder`.
Checks that an error is raised when method is invalid.
"""
n_lons = 6
n_lats = 5
lon_bounds = (-180, 180)
lat_bounds = (-90, 90)
face_src = _gridlike_mesh_cube(n_lons, n_lats, location="face")
edge_src = _gridlike_mesh_cube(n_lons, n_lats, location="edge")
node_src = _gridlike_mesh_cube(n_lons, n_lats, location="node")
tgt = _grid_cube(n_lons, n_lats, lon_bounds, lat_bounds, circular=True)
with pytest.raises(ValueError):
_ = MeshToGridESMFRegridder(face_src, tgt, method="other")
with pytest.raises(ValueError) as excinfo:
_ = MeshToGridESMFRegridder(node_src, tgt, method="conservative")
expected_message = (
"Conservative regridding requires a source cube located on "
"the face of a cube, target cube had the node location.")
assert expected_message in str(excinfo.value)
with pytest.raises(ValueError) as excinfo:
_ = MeshToGridESMFRegridder(edge_src, tgt, method="bilinear")
expected_message = (
"Bilinear regridding requires a source cube with a node "
"or face location, target cube had the edge location.")
assert expected_message in str(excinfo.value)
def test_invalid_args():
"""
Test for :func:`esmf_regrid.experimental.unstructured_scheme.regrid_unstructured_to_rectilinear`.
Tests that an appropriate error is raised when arguments are invalid.
"""
n_lons = 6
n_lats = 5
lon_bounds = (-180, 180)
lat_bounds = (-90, 90)
node_src = _gridlike_mesh_cube(n_lons, n_lats, location="node")
edge_src = _gridlike_mesh_cube(n_lons, n_lats, location="edge")
face_src = _gridlike_mesh_cube(n_lons, n_lats, location="face")
tgt = _grid_cube(n_lons, n_lats, lon_bounds, lat_bounds, circular=True)
with pytest.raises(ValueError):
_ = regrid_unstructured_to_rectilinear(tgt, tgt, method="bilinear")
with pytest.raises(ValueError):
_ = regrid_unstructured_to_rectilinear(face_src, tgt, method="other")
with pytest.raises(ValueError) as excinfo:
_ = regrid_unstructured_to_rectilinear(node_src,
tgt,
method="conservative")
expected_message = (
"Conservative regridding requires a source cube located on "
"the face of a cube, target cube had the node location.")
assert expected_message in str(excinfo.value)
with pytest.raises(ValueError) as excinfo:
_ = regrid_unstructured_to_rectilinear(edge_src,
tgt,
method="bilinear")
expected_message = (
"Bilinear regridding requires a source cube with a node "
"or face location, target cube had the edge location.")
assert expected_message in str(excinfo.value)
def test_invalid_resolution():
"""
Test initialisation of :func:`esmf_regrid.experimental.unstructured_scheme.MeshToGridESMFRegridder`.
Checks that an error is raised when the resolution is invalid.
"""
n_lons = 6
n_lats = 5
lon_bounds = (-180, 180)
lat_bounds = (-90, 90)
src = _gridlike_mesh_cube(n_lons, n_lats, location="face")
tgt = _grid_cube(n_lons, n_lats, lon_bounds, lat_bounds, circular=True)
with pytest.raises(ValueError) as excinfo:
_ = MeshToGridESMFRegridder(src,
tgt,
method="conservative",
resolution=-1)
expected_message = "resolution must be a positive integer."
assert expected_message in str(excinfo.value)
with pytest.raises(ValueError) as excinfo:
_ = MeshToGridESMFRegridder(src, tgt, method="bilinear", resolution=4)
expected_message = "resolution can only be set for conservative regridding."
assert expected_message in str(excinfo.value)
def test_bilinear():
"""
Basic test for :func:`esmf_regrid.experimental.unstructured_scheme.regrid_unstructured_to_rectilinear`.
Tests with the bilinear method.
"""
n_lons = 6
n_lats = 5
lon_bounds = (-180, 180)
lat_bounds = (-90, 90)
src = _gridlike_mesh_cube(n_lons, n_lats, location="node")
tgt = _grid_cube(n_lons, n_lats, lon_bounds, lat_bounds, circular=True)
# Ensure data in the target grid is different to the expected data.
# i.e. target grid data is all zero, expected data is all one
tgt.data[:] = 0
src = _add_metadata(src)
src.data[:] = 1 # Ensure all data in the source is one.
result = regrid_unstructured_to_rectilinear(src, tgt, method="bilinear")
expected_data = np.ones([n_lats, n_lons])
expected_cube = _add_metadata(tgt)
# Lenient check for data.
assert np.allclose(expected_data, result.data)
# Check metadata and scalar coords.
expected_cube.data = result.data
assert expected_cube == result
def _make_mesh_to_grid_regridder(method="conservative",
resolution=None,
grid_dims=1,
circular=True):
src_lons = 3
src_lats = 4
tgt_lons = 5
tgt_lats = 6
lon_bounds = (-180, 180)
lat_bounds = (-90, 90)
if grid_dims == 1:
tgt = _grid_cube(tgt_lons,
tgt_lats,
lon_bounds,
lat_bounds,
circular=circular)
else:
tgt = _curvilinear_cube(tgt_lons, tgt_lats, lon_bounds, lat_bounds)
tgt.coord("longitude").var_name = "longitude"
tgt.coord("latitude").var_name = "latitude"
if method == "bilinear":
location = "node"
else:
location = "face"
src = _gridlike_mesh_cube(src_lons, src_lats, location=location)
rg = MeshToGridESMFRegridder(src,
tgt,
method=method,
mdtol=0.5,
resolution=resolution)
return rg, src
def test_bilinear():
"""
Basic test for :func:`esmf_regrid.experimental.unstructured_scheme.GridToMeshESMFRegridder`.
Tests with method="bilinear".
"""
n_lons = 6
n_lats = 5
lon_bounds = (-180, 180)
lat_bounds = (-90, 90)
src = _grid_cube(n_lons, n_lats, lon_bounds, lat_bounds, circular=True)
face_tgt = _gridlike_mesh_cube(n_lons, n_lats, location="face")
node_tgt = _gridlike_mesh_cube(n_lons, n_lats, location="node")
src = _add_metadata(src)
src.data[:] = 1 # Ensure all data in the source is one.
face_regridder = GridToMeshESMFRegridder(src, face_tgt, method="bilinear")
node_regridder = GridToMeshESMFRegridder(src, node_tgt, method="bilinear")
assert face_regridder.regridder.method == "bilinear"
assert node_regridder.regridder.method == "bilinear"
face_expected_data = np.ones_like(face_tgt.data)
node_expected_data = np.ones_like(node_tgt.data)
face_result = face_regridder(src)
node_result = node_regridder(src)
# Lenient check for data.
assert np.allclose(face_expected_data, face_result.data)
assert np.allclose(node_expected_data, node_result.data)
# Check metadata and scalar coords.
face_expected_cube = _add_metadata(face_tgt)
node_expected_cube = _add_metadata(node_tgt)
face_expected_cube.data = face_result.data
node_expected_cube.data = node_result.data
assert face_expected_cube == face_result
assert node_expected_cube == node_result
def test_default_mdtol():
"""
Test initialisation of :func:`esmf_regrid.experimental.unstructured_scheme.MeshToGridESMFRegridder`.
Checks that default mdtol values are as expected.
"""
n_lons = 6
n_lats = 5
lon_bounds = (-180, 180)
lat_bounds = (-90, 90)
src = _gridlike_mesh_cube(n_lons, n_lats)
tgt = _grid_cube(n_lons, n_lats, lon_bounds, lat_bounds, circular=True)
rg_con = MeshToGridESMFRegridder(src, tgt, method="conservative")
assert rg_con.mdtol == 1
rg_bi = MeshToGridESMFRegridder(src, tgt, method="bilinear")
assert rg_bi.mdtol == 0