def test_cells_dict_utils():
# No pyvista object
with pytest.raises(ValueError):
cells.get_mixed_cells(None)
with pytest.raises(ValueError):
cells.get_mixed_cells(np.zeros(shape=[3, 3]))
cells_arr = np.array([3, 0, 1, 2, 3, 3, 4, 5])
cells_types = np.array([vtk.VTK_TRIANGLE] * 2)
assert np.all(
cells.generate_cell_offsets(cells_arr, cells_types) ==
cells.generate_cell_offsets(cells_arr, cells_types))
# Non-integer type
with pytest.raises(ValueError):
cells.generate_cell_offsets(cells_arr, cells_types.astype(np.float32))
with pytest.raises(ValueError):
cells.generate_cell_offsets_loop(cells_arr,
cells_types.astype(np.float32))
# Inconsistency of cell array lengths
with pytest.raises(ValueError):
cells.generate_cell_offsets(np.array(cells_arr.tolist() + [6]),
cells_types)
with pytest.raises(ValueError):
cells.generate_cell_offsets_loop(np.array(cells_arr.tolist() + [6]),
cells_types)
with pytest.raises(ValueError):
cells.generate_cell_offsets(
cells_arr, np.array(cells_types.tolist() + [vtk.VTK_TRIANGLE]))
with pytest.raises(ValueError):
cells.generate_cell_offsets_loop(
cells_arr, np.array(cells_types.tolist() + [vtk.VTK_TRIANGLE]))
# Unknown cell type
np.all(
cells.generate_cell_offsets(cells_arr, cells_types) ==
cells.generate_cell_offsets(cells_arr, np.array([255, 255])))
def _from_arrays(self, offset, cells, cell_type, points, deep=True):
"""Create VTK unstructured grid from numpy arrays.
Parameters
----------
offset : np.ndarray dtype=np.int64
Array indicating the start location of each cell in the cells
array. Set to ``None`` when using VTK 9+.
cells : np.ndarray dtype=np.int64
Array of cells. Each cell contains the number of points in the
cell and the node numbers of the cell.
cell_type : np.uint8
Cell types of each cell. Each cell type numbers can be found from
vtk documentation. See example below.
points : np.ndarray
Numpy array containing point locations.
Examples
--------
>>> import numpy
>>> import vtk
>>> import pyvista
>>> offset = np.array([0, 9])
>>> cells = np.array([8, 0, 1, 2, 3, 4, 5, 6, 7, 8, 8, 9, 10, 11, 12, 13, 14, 15])
>>> cell_type = np.array([vtk.VTK_HEXAHEDRON, vtk.VTK_HEXAHEDRON], np.int8)
>>> cell1 = np.array([[0, 0, 0],
... [1, 0, 0],
... [1, 1, 0],
... [0, 1, 0],
... [0, 0, 1],
... [1, 0, 1],
... [1, 1, 1],
... [0, 1, 1]])
>>> cell2 = np.array([[0, 0, 2],
... [1, 0, 2],
... [1, 1, 2],
... [0, 1, 2],
... [0, 0, 3],
... [1, 0, 3],
... [1, 1, 3],
... [0, 1, 3]])
>>> points = np.vstack((cell1, cell2))
>>> grid = pyvista.UnstructuredGrid(offset, cells, cell_type, points)
"""
# Convert to vtk arrays
vtkcells = CellArray(cells, cell_type.size, deep)
if cell_type.dtype != np.uint8:
cell_type = cell_type.astype(np.uint8)
cell_type_np = cell_type
cell_type = _vtk.numpy_to_vtk(cell_type, deep=deep)
# Convert points to vtkPoints object
points = pyvista.vtk_points(points, deep=deep)
self.SetPoints(points)
# vtk9 does not require an offset array
if _vtk.VTK9:
if offset is not None:
warnings.warn('VTK 9 no longer accepts an offset array',
stacklevel=3)
self.SetCells(cell_type, vtkcells)
else:
if offset is None:
offset = generate_cell_offsets(cells, cell_type_np)
self.SetCells(cell_type, numpy_to_idarr(offset), vtkcells)