def stagger(field: CenteredGrid,
face_function: Callable,
extrapolation: math.extrapolation.Extrapolation,
type: type = StaggeredGrid):
"""
Creates a new grid by evaluating `face_function` given two neighbouring cells.
One layer of missing cells is inferred from the extrapolation.
This method returns a Field of type `type` which must be either StaggeredGrid or CenteredGrid.
When returning a StaggeredGrid, the new values are sampled at the faces of neighbouring cells.
When returning a CenteredGrid, the new grid has the same resolution as `field`.
Args:
field: centered grid
face_function: function mapping (value1: Tensor, value2: Tensor) -> center_value: Tensor
extrapolation: extrapolation mode of the returned grid. Has no effect on the values.
type: one of (StaggeredGrid, CenteredGrid)
field: CenteredGrid:
face_function: Callable:
extrapolation: math.extrapolation.Extrapolation:
type: type: (Default value = StaggeredGrid)
Returns:
grid of type matching the `type` argument
"""
all_lower = []
all_upper = []
if type == StaggeredGrid:
for dim in field.shape.spatial.names:
lo_valid, up_valid = extrapolation.valid_outer_faces(dim)
width_lower = {dim: (int(lo_valid), int(up_valid) - 1)}
width_upper = {
dim: (int(lo_valid or up_valid) - 1, int(lo_valid
and up_valid))
}
all_lower.append(
math.pad(field.values, width_lower, field.extrapolation))
all_upper.append(
math.pad(field.values, width_upper, field.extrapolation))
all_upper = math.stack(all_upper, channel('vector'))
all_lower = math.stack(all_lower, channel('vector'))
values = face_function(all_lower, all_upper)
result = StaggeredGrid(values,
bounds=field.bounds,
extrapolation=extrapolation)
assert result.shape.spatial == field.shape.spatial
return result
elif type == CenteredGrid:
left, right = math.shift(field.values, (-1, 1),
padding=field.extrapolation,
stack_dim=channel('vector'))
values = face_function(left, right)
return CenteredGrid(values,
bounds=field.bounds,
extrapolation=extrapolation)
else:
raise ValueError(type)
def __mul__(self, other):
if not isinstance(other, Box):
return NotImplemented
lower = self._lower.vector.unstack(
self.spatial_rank) + other._lower.vector.unstack(self.spatial_rank)
upper = self._upper.vector.unstack(
self.spatial_rank) + other._upper.vector.unstack(self.spatial_rank)
names = self._upper.vector.item_names + other._upper.vector.item_names
lower = math.stack(lower, math.channel(vector=names))
upper = math.stack(upper, math.channel(vector=names))
return Box(lower, upper)
def staggered_points(self, dimension):
idx_zyx = np.meshgrid(*[
np.arange(0.5, dim + 1.5, 1) if dim != dimension else np.arange(
0, dim + 1, 1) for dim in self.resolution
],
indexing="ij")
return math.expand_dims(math.stack(idx_zyx, axis=-1), 0)
def union(*geometries) -> Geometry:
"""
Union of the given geometries.
A point lies inside the union if it lies within at least one of the geometries.
Args:
geometries: arbitrary geometries with same spatial dims. Arbitrary batch dims are allowed.
*geometries:
Returns:
union Geometry
"""
if len(geometries) == 1 and isinstance(geometries[0], (tuple, list)):
geometries = geometries[0]
if len(geometries) == 0:
return NO_GEOMETRY
elif len(geometries) == 1:
return geometries[0]
elif all(type(g) == type(geometries[0]) for g in geometries):
attrs = variable_attributes(geometries[0])
values = {
a: math.stack([getattr(g, a) for g in geometries],
math.instance('union'))
for a in attrs
}
return copy_with(geometries[0], **values)
else:
base_geometries = ()
for geometry in geometries:
base_geometries += geometry.geometries if isinstance(
geometry, Union) else (geometry, )
return Union(base_geometries)
def at_faces(self, face_dimension_xyz):
dims = range(self.spatial_rank)
face_dimension_zyx = len(
dims) - face_dimension_xyz - 1 # 0=Z, 1=Y, 2=X, etc.
components = []
for d in dims: # z,y,x
if d == face_dimension_zyx:
components.append(self.staggered[..., len(dims) - d - 1])
else:
# Interpolate other components
vq = self.staggered[..., len(dims) - d - 1]
t = vq
for d2 in dims: # z,y,x
slices1 = [(slice(1, None) if i == d2 else slice(None))
for i in dims]
slices2 = [(slice(-1) if i == d2 else slice(None))
for i in dims]
t = t[[slice(None)] + slices1] + t[[slice(None)] + slices2]
if d2 == d:
t = math.pad(
t, [[0, 0]] + [([0, 1] if i == d2 else [0, 0])
for i in dims]) / 2
else:
t = math.pad(
t, [[0, 0]] + [([1, 0] if i == d2 else [0, 0])
for i in dims]) / 2
components.append(t)
return math.stack(components[::-1], axis=-1)
def reduce_sample(field: Field, geometry: Geometry, dim=channel('vector')) -> math.Tensor:
"""
Similar to `sample()`, but matches channel dimensions of `geometry` with channel dimensions of this field.
Currently, `geometry` may have at most one channel dimension.
See Also:
`sample()`, `Field.at()`, [Resampling overview](https://tum-pbs.github.io/PhiFlow/Fields.html#resampling-fields).
Args:
field: Source `Field` to sample.
geometry: Single or batched `phi.geom.Geometry`.
dim: Dimension of result, resulting from reduction of channel dimensions.
Returns:
Sampled values as a `phi.math.Tensor`
"""
if isinstance(field, SampledField) and field.elements.shallow_equals(geometry):
return field.values
if geometry.shape.channel: # Reduce this dimension
assert geometry.shape.channel.rank == 1, "Only single-dimension reduction supported."
if field.shape.channel.volume > 1:
assert field.shape.channel.volume == geometry.shape.channel.volume, f"Cannot sample field with channels {field.shape.channel} at elements with channels {geometry.shape.channel}."
components = unstack(field, field.shape.channel.name)
sampled = [c._sample(p) for c, p in zip(components, geometry.unstack(geometry.shape.channel.name))]
else:
sampled = [field._sample(p) for p in geometry.unstack(geometry.shape.channel.name)]
dim = dim._with_item_names(geometry.shape.channel.item_names)
return math.stack(sampled, dim)
else: # Nothing to reduce
return field._sample(geometry)
def sample(field: Field, geometry: Geometry) -> math.Tensor:
"""
Computes the field value inside the volume of the (batched) `geometry`.
The field value may be determined by integrating over the volume, sampling the central value or any other way.
The batch dimensions of `geometry` are matched with this field.
The `geometry` must not share any channel dimensions with this field.
Spatial dimensions of `geometry` can be used to sample a grid of geometries.
See Also:
`reduce_sample()`, `Field.at()`, [Resampling overview](https://tum-pbs.github.io/PhiFlow/Fields.html#resampling-fields).
Args:
field: Source `Field` to sample.
geometry: Single or batched `phi.geom.Geometry`.
Returns:
Sampled values as a `phi.math.Tensor`
"""
assert all(dim not in field.shape for dim in geometry.shape.channel)
if isinstance(field, SampledField) and field.elements.shallow_equals(geometry) and not geometry.shape.channel:
return field.values
if geometry.shape.channel:
sampled = [field._sample(p) for p in geometry.unstack(geometry.shape.channel.name)]
return math.stack(sampled, geometry.shape.channel)
else:
return field._sample(geometry)
def lies_inside(self, location: math.Tensor):
if self.geometries.shape in location.shape:
location = location.unstack(self.geometries.shape.name)
else:
location = [location] * len(self.geometries)
inside = [g.lies_inside(loc) for g, loc in zip(self.geometries, location)]
return math.stack(inside, self.geometries.shape)
def upsample2x(tensor, interpolation="LINEAR"):
if interpolation.lower() != "linear":
raise ValueError("Only linear interpolation supported")
dims = range(spatial_rank(tensor))
vlen = tensor.shape[-1]
spatial_dims = tensor.shape[1:-1]
tensor = math.pad(tensor,
[[0, 0]] + [[1, 1]] * spatial_rank(tensor) + [[0, 0]],
"SYMMETRIC")
for dim in dims:
left_slices_1 = [(slice(2, None) if i == dim else slice(None))
for i in dims]
left_slices_2 = [(slice(1, -1) if i == dim else slice(None))
for i in dims]
right_slices_1 = [(slice(1, -1) if i == dim else slice(None))
for i in dims]
right_slices_2 = [(slice(-2) if i == dim else slice(None))
for i in dims]
left = 0.75 * tensor[[slice(None)] + left_slices_2 +
[slice(None)]] + 0.25 * tensor[
[slice(None)] + left_slices_1 + [slice(None)]]
right = 0.25 * tensor[[slice(None)] + right_slices_2 + [
slice(None)
]] + 0.75 * tensor[[slice(None)] + right_slices_1 + [slice(None)]]
combined = math.stack([right, left], axis=2 + dim)
tensor = math.reshape(combined, [-1] + [
spatial_dims[dim] * 2 if i == dim else tensor.shape[i + 1]
for i in dims
] + [vlen])
return tensor
def with_extrapolation(self, extrapolation: math.Extrapolation):
if all(
extrapolation.valid_outer_faces(dim) ==
self.extrapolation.valid_outer_faces(dim)
for dim in self.resolution.names):
return StaggeredGrid(self.values,
extrapolation=extrapolation,
bounds=self.bounds)
else:
values = []
for dim, component in zip(self.shape.spatial.names,
self.values.unstack('vector')):
old_lo, old_hi = [
int(v) for v in self.extrapolation.valid_outer_faces(dim)
]
new_lo, new_hi = [
int(v) for v in extrapolation.valid_outer_faces(dim)
]
widths = (new_lo - old_lo, new_hi - old_hi)
values.append(
math.pad(component, {dim: widths}, self.extrapolation))
values = math.stack(values, channel('vector'))
return StaggeredGrid(values,
extrapolation=extrapolation,
bounds=self.bounds)
def test_stacked_shapes(self):
t0 = math.ones(batch(batch=10) & spatial(x=4, y=3) & channel(vector=2))
for dim in t0.shape.names:
tensors = t0.unstack(dim)
stacked = math.stack(tensors, t0.shape[dim].with_sizes([None]))
self.assertEqual(set(t0.shape.names), set(stacked.shape.names))
self.assertEqual(t0.shape.volume, stacked.shape.volume)
def distribute_points(density, particles_per_cell=1, distribution='uniform'):
"""
Distribute points according to the distribution specified in density.
:param density: binary tensor
:param particles_per_cell: integer
:param distribution: 'uniform' or 'center'
:return: tensor of shape (batch_size, point_count, rank)
"""
assert distribution in ('center', 'uniform')
index_array = []
batch_size = math.staticshape(density)[0] if math.staticshape(density)[0] is not None else 1
for batch in range(batch_size):
indices = math.where(density[batch, ..., 0] > 0)
indices = math.to_float(indices)
temp = []
for _ in range(particles_per_cell):
if distribution == 'center':
temp.append(indices + 0.5)
elif distribution == 'uniform':
temp.append(indices + math.random_uniform(math.shape(indices)))
index_array.append(math.concat(temp, axis=0))
try:
index_array = math.stack(index_array)
return index_array
except ValueError:
raise ValueError("all arrays in the batch must have the same number of active cells.")
def stack(geometries: List[Geometry], dim: Shape):
""" Stacks `geometries` along `dim`. The size of `dim` is ignored. """
if all(type(g) == type(geometries[0]) and not isinstance(g, GridCell) for g in geometries):
attrs = variable_attributes(geometries[0])
new_attributes = {a: math.stack([getattr(g, a) for g in geometries], dim) for a in attrs}
return copy_with(geometries[0], **new_attributes)
return GeometryStack(math.layout(geometries, dim))
def downsample2x(grid: Grid) -> GridType:
"""
Reduces the number of sample points by a factor of 2 in each spatial dimension.
The new values are determined via linear interpolation.
See Also:
`upsample2x()`.
Args:
grid: `CenteredGrid` or `StaggeredGrid`.
Returns:
`Grid` of same type as `grid`.
"""
if isinstance(grid, CenteredGrid):
values = math.downsample2x(grid.values, grid.extrapolation)
return CenteredGrid(values,
bounds=grid.bounds,
extrapolation=grid.extrapolation)
elif isinstance(grid, StaggeredGrid):
values = []
for dim, centered_grid in zip(grid.shape.spatial.names,
unstack(grid, 'vector')):
odd_discarded = centered_grid.values[{dim: slice(None, None, 2)}]
others_interpolated = math.downsample2x(
odd_discarded,
grid.extrapolation,
dims=grid.shape.spatial.without(dim))
values.append(others_interpolated)
return StaggeredGrid(math.stack(values, channel('vector')),
bounds=grid.bounds,
extrapolation=grid.extrapolation)
else:
raise ValueError(type(grid))
def bake_extrapolation(grid: GridType) -> GridType:
"""
Pads `grid` with its current extrapolation.
For `StaggeredGrid`s, the resulting grid will have a consistent shape, independent of the original extrapolation.
Args:
grid: `CenteredGrid` or `StaggeredGrid`.
Returns:
Padded grid with extrapolation `phi.math.extrapolation.NONE`.
"""
if grid.extrapolation == math.extrapolation.NONE:
return grid
if isinstance(grid, StaggeredGrid):
values = grid.values.unstack('vector')
padded = []
for dim, value in zip(grid.shape.spatial.names, values):
lower, upper = grid.extrapolation.valid_outer_faces(dim)
padded.append(
math.pad(value, {dim: (0 if lower else 1, 0 if upper else 1)},
grid.extrapolation))
return StaggeredGrid(math.stack(padded, channel('vector')),
bounds=grid.bounds,
extrapolation=math.extrapolation.NONE)
elif isinstance(grid, CenteredGrid):
return pad(grid, 1).with_extrapolation(math.extrapolation.NONE)
else:
raise ValueError(f"Not a valid grid: {grid}")
def test_stacked_get(self):
t0 = math.ones(batch(batch=10) & spatial(x=4, y=3) & channel(vector=2))
tensors = t0.unstack('vector')
stacked = math.stack(tensors, channel('channel'))
self.assertEqual(tensors, stacked.channel.unstack())
assert tensors[0] is stacked.channel[0]
assert tensors[1] is stacked.channel[1:2].channel.unstack()[0]
self.assertEqual(4, len(stacked.x.unstack()))
def test_plot_multi_1d(self):
self._test_plot(
CenteredGrid(
lambda x: math.stack({
'sin': math.sin(x),
'cos': math.cos(x)
}, channel('curves')),
x=100,
bounds=Box(x=2 * math.pi)))
def unstack_staggered_tensor(data: Tensor,
extrapolation: math.Extrapolation) -> TensorStack:
sliced = []
for dim, component in zip(data.shape.spatial.names,
data.unstack('vector')):
lo_valid, up_valid = extrapolation.valid_outer_faces(dim)
slices = {d: slice(0, -1) for d in data.shape.spatial.names}
slices[dim] = slice(int(not lo_valid), -int(not up_valid) or None)
sliced.append(component[slices])
return math.stack(sliced, channel('vector'))
def stack(fields, dim: Shape, dim_bounds: Box = None):
"""
Stacks the given `SampledField`s along `dim`.
See Also:
`concat()`.
Args:
fields: List of matching `SampledField` instances.
dim: Stack dimension as `Shape`. Size is ignored.
Returns:
`SampledField` matching stacked fields.
"""
assert all(
isinstance(f, SampledField) for f in fields
), f"All fields must be SampledFields of the same type but got {fields}"
assert all(
isinstance(f, type(fields[0])) for f in fields
), f"All fields must be SampledFields of the same type but got {fields}"
if any(f.extrapolation != fields[0].extrapolation for f in fields):
raise NotImplementedError("Concatenating extrapolations not supported")
if isinstance(fields[0], Grid):
values = math.stack([f.values for f in fields], dim)
if spatial(dim):
if dim_bounds is None:
dim_bounds = Box(**{dim.name: len(fields)})
return type(fields[0])(values,
extrapolation=fields[0].extrapolation,
bounds=fields[0].bounds * dim_bounds)
else:
return fields[0].with_values(values)
elif isinstance(fields[0], PointCloud):
elements = geom.stack([f.elements for f in fields], dim=dim)
values = math.stack([f.values for f in fields], dim=dim)
colors = math.stack([f.color for f in fields], dim=dim)
return PointCloud(elements=elements,
values=values,
color=colors,
extrapolation=fields[0].extrapolation,
add_overlapping=fields[0]._add_overlapping,
bounds=fields[0]._bounds)
raise NotImplementedError(type(fields[0]))
def _sample(self, geometry: Geometry, outside_handling='discard') -> Tensor:
if geometry == self.elements:
return self.values
elif isinstance(geometry, GridCell):
return self.grid_scatter(geometry.bounds, geometry.resolution, outside_handling)
elif isinstance(geometry, GeometryStack):
sampled = [self._sample(g) for g in geometry.geometries]
return math.stack(sampled, geometry.geometries.shape)
else:
raise NotImplementedError()
def getpoints(box, resolution):
idx_zyx = np.meshgrid(*[
np.linspace(0.5 / dim, 1 - 0.5 / dim, dim) for dim in resolution
],
indexing="ij")
local_coords = math.expand_dims(math.stack(idx_zyx, axis=-1),
0).astype(np.float32)
points = box.local_to_global(local_coords)
return CenteredGrid(points,
box,
name='grid_centers(%s, %s)' % (box, resolution),
flags=[SAMPLE_POINTS])
def at_centers(self):
rank = self.spatial_rank
dims = range(rank)
df_dq = []
for d in dims: # z,y,x
upper_slices = [(slice(1, None) if i == d else slice(-1))
for i in dims]
lower_slices = [(slice(-1) if i == d else slice(-1)) for i in dims]
sum = self.staggered[[slice(None)] + upper_slices + [rank - d - 1]] +\
self.staggered[[slice(None)] + lower_slices + [rank - d - 1]]
df_dq.append(sum / rank)
return math.stack(df_dq[::-1], axis=-1)
def test_stacked_native(self):
t0 = math.ones(batch(batch=10) & spatial(x=4, y=3) & channel(vector=2))
tensors = t0.unstack('vector')
stacked = math.stack(tensors, channel('vector2'))
math.assert_close(stacked, t0)
self.assertEqual((10, 4, 3, 2), stacked.native(stacked.shape).shape)
self.assertEqual(
(4, 3, 2, 10),
stacked.native(order=('x', 'y', 'vector2', 'batch')).shape)
self.assertEqual(
(2, 10, 3, 4),
stacked.native(order=('vector2', 'batch', 'y', 'x')).shape
) # this should re-stack since only the stacked dimension position is different
def closest_values(self, points: Geometry):
assert 'vector' not in points.shape
if 'staggered_direction' in points.shape:
points = points.unstack('staggered_direction')
channels = [
component.closest_values(p)
for p, component in zip(points, self.vector.unstack())
]
else:
channels = [
component.closest_values(points)
for component in self.vector.unstack()
]
return math.stack(channels, channel('vector'))
def _central_diff_nd(field, dims):
field = math.pad(field,
[[0, 0]] + [[1, 1]] * spatial_rank(field) + [[0, 0]],
"symmetric")
df_dq = []
for dimension in dims:
upper_slices = [(slice(2, None) if i == dimension else slice(1, -1))
for i in dims]
lower_slices = [(slice(-2) if i == dimension else slice(1, -1))
for i in dims]
diff = field[[slice(None)] + upper_slices +
[0]] - field[[slice(None)] + lower_slices + [0]]
df_dq.append(diff)
return math.stack(df_dq[::-1], axis=-1)
def _forward_diff_nd(field, dims):
df_dq = []
for dimension in dims:
upper_slices = [(slice(1, None) if i == dimension else slice(None))
for i in dims]
lower_slices = [(slice(-1) if i == dimension else slice(None))
for i in dims]
diff = field[[slice(None)] + upper_slices] - field[[slice(None)] +
lower_slices]
padded = math.pad(diff,
[[0, 0]] + [([0, 1] if i == dimension else [0, 0])
for i in dims])
df_dq.append(padded)
return math.stack(df_dq[::-1], axis=-1)
def _stagger_sample(self, box, resolution):
"""
Samples this field on a staggered grid.
In addition to sampling, extrapolates the field using an occupancy mask generated from the points.
:param box: physical dimensions of the grid
:param resolution: grid resolution
:return: StaggeredGrid
"""
resolution = np.array(resolution)
valid_indices = math.to_int(math.floor(self.sample_points))
valid_indices = math.minimum(math.maximum(0, valid_indices), resolution - 1)
# Correct format for math.scatter
valid_indices = batch_indices(valid_indices)
active_mask = math.scatter(self.sample_points, valid_indices, 1, math.concat([[valid_indices.shape[0]], resolution, [1]], axis=-1), duplicates_handling='any')
mask = math.pad(active_mask, [[0, 0]] + [[1, 1]] * self.rank + [[0, 0]], "constant")
if isinstance(self.data, (int, float, np.ndarray)):
values = math.zeros_like(self.sample_points) + self.data
else:
values = self.data
result = []
ones_1d = math.unstack(math.ones_like(values), axis=-1)[0]
staggered_shape = [i + 1 for i in resolution]
dx = box.size / resolution
dims = range(len(resolution))
for d in dims:
staggered_offset = math.stack([(0.5 * dx[i] * ones_1d if i == d else 0.0 * ones_1d) for i in dims], axis=-1)
indices = math.to_int(math.floor(self.sample_points + staggered_offset))
valid_indices = math.maximum(0, math.minimum(indices, resolution))
valid_indices = batch_indices(valid_indices)
values_d = math.expand_dims(math.unstack(values, axis=-1)[d], axis=-1)
result.append(math.scatter(self.sample_points, valid_indices, values_d, [indices.shape[0]] + staggered_shape + [1], duplicates_handling=self.mode))
d_slice = tuple([(slice(0, -2) if i == d else slice(1,-1)) for i in dims])
u_slice = tuple([(slice(2, None) if i == d else slice(1,-1)) for i in dims])
active_mask = math.minimum(mask[(slice(None),) + d_slice + (slice(None),)], active_mask)
active_mask = math.minimum(mask[(slice(None),) + u_slice + (slice(None),)], active_mask)
staggered_tensor_prep = unstack_staggered_tensor(math.concat(result, axis=-1))
grid_values = StaggeredGrid(staggered_tensor_prep)
# Fix values at boundary of liquids (using StaggeredGrid these might not receive a value, so we replace it with a value inside the liquid)
grid_values, _ = extrapolate(grid_values, active_mask, voxel_distance=2)
return grid_values
def sample_at(self, points):
points_rank = math.spatial_rank(points)
src_rank = math.spatial_rank(self.location)
# --- Expand shapes to format (batch_size, points_dims..., src_dims..., channels) ---
points = math.expand_dims(points, axis=-2, number=src_rank)
src_points = math.expand_dims(self.location,
axis=-2,
number=points_rank)
src_strength = math.expand_dims(self.strength, axis=-1)
src_strength = math.batch_align(src_strength, 0, self.location)
src_strength = math.expand_dims(src_strength,
axis=-1,
number=points_rank)
src_axes = tuple(range(-2, -2 - src_rank, -1))
# --- Compute distances and falloff ---
distances = points - src_points
if self.falloff is not None:
raise NotImplementedError()
# distances_squared = math.sum(distances ** 2, axis=-1, keepdims=True)
# unit_distances = distances / math.sqrt(distances_squared)
# strength = src_strength * math.exp(-distances_squared)
else:
strength = src_strength
# --- Compute velocities ---
if math.staticshape(points)[-1] == 2: # Curl in 2D
dist_1, dist_2 = math.unstack(distances, axis=-1)
if GLOBAL_AXIS_ORDER.is_x_first:
velocity = strength * math.stack([-dist_2, dist_1], axis=-1)
else:
velocity = strength * math.stack([dist_2, -dist_1], axis=-1)
elif math.staticshape(points)[-1] == 3: # Curl in 3D
raise NotImplementedError('not yet implemented')
else:
raise AssertionError(
'Vector product not available in > 3 dimensions')
velocity = math.sum(velocity, axis=src_axes)
return velocity
def extrapolate_valid(grid: GridType,
valid: GridType,
distance_cells=1) -> tuple:
"""
Extrapolates values of `grid` which are marked by nonzero values in `valid` using `phi.math.extrapolate_valid_values().
If `values` is a StaggeredGrid, its components get extrapolated independently.
Args:
grid: Grid holding the values for extrapolation
valid: Grid (same type as `values`) marking the positions for extrapolation with nonzero values
distance_cells: Number of extrapolation steps
Returns:
grid: Grid with extrapolated values.
valid: binary Grid marking all valid values after extrapolation.
"""
assert isinstance(
valid, type(grid)), 'Type of valid Grid must match type of grid.'
if isinstance(grid, CenteredGrid):
new_values, new_valid = extrapolate_valid_values(
grid.values, valid.values, distance_cells)
return grid.with_values(new_values), valid.with_values(new_valid)
elif isinstance(grid, StaggeredGrid):
new_values = []
new_valid = []
for cgrid, cvalid in zip(unstack(grid, 'vector'),
unstack(valid, 'vector')):
new_tensor, new_mask = extrapolate_valid(
cgrid, valid=cvalid, distance_cells=distance_cells)
new_values.append(new_tensor.values)
new_valid.append(new_mask.values)
return grid.with_values(math.stack(new_values,
channel(grid))), valid.with_values(
math.stack(
new_valid, channel(grid)))
else:
raise NotImplementedError()
def test_tensor_from_tensor(self):
ref = math.stack([math.zeros(spatial(x=5)),
math.zeros(spatial(x=4))], batch('stack'))
for backend in BACKENDS:
with backend:
tens = math.tensor(ref, convert=False)
self.assertEqual(math.NUMPY, math.choose_backend(tens))
self.assertEqual(2, tens.shape.get_size('stack'))
self.assertEqual(('stack', 'x'), tens.shape.names)
tens = math.tensor(ref)
self.assertEqual(backend, math.choose_backend(tens))
self.assertEqual(backend, math.choose_backend(tens.stack[0]))
self.assertEqual(backend, math.choose_backend(tens.stack[1]))
tens = math.tensor(ref, batch('n1', 'n2'))
self.assertEqual(backend, math.choose_backend(tens))
