pyvista.DataSet.cell_neighbors

DataSet.cell_neighbors(ind: int, connections: str = 'points') → List[int]

Get the cell neighbors of the ind-th cell.

Concrete implementation of vtkDataSet’s GetCellNeighbors.

Parameters:

indint

Cell ID.

connectionsstr, default: “points”

Describe how the neighbor cell(s) must be connected to the current cell to be considered as a neighbor. Can be either 'points', 'edges' or 'faces'.

Returns:

List[int]

List of neighbor cells IDs for the ind-th cell.

Warning

For a pyvista.ExplicitStructuredGrid, use pyvista.ExplicitStructuredGrid.neighbors().

See also

pyvista.DataSet.cell_neighbors_levels

Examples

>>> from pyvista import examples
>>> mesh = examples.load_airplane()

Get the neighbor cell ids that have at least one point in common with the 0-th cell.

>>> mesh.cell_neighbors(0, "points")
[1, 2, 3, 388, 389, 11, 12, 395, 14, 209, 211, 212]

Get the neighbor cell ids that have at least one edge in common with the 0-th cell.

>>> mesh.cell_neighbors(0, "edges")
[1, 3, 12]

For unstructured grids with cells of dimension 3 (Tetrahedron for example), cell neighbors can be defined using faces.

>>> mesh = examples.download_tetrahedron()
>>> mesh.cell_neighbors(0, "faces")
[1, 5, 7]

Show a visual example.

>>> from functools import partial
>>> import pyvista as pv
>>> mesh = pv.Sphere(theta_resolution=10)
>>>
>>> pl = pv.Plotter(shape=(1, 2))
>>> pl.link_views()
>>> add_point_labels = partial(
...     pl.add_point_labels,
...     text_color="white",
...     font_size=20,
...     shape=None,
...     show_points=False,
... )
>>>
>>> for i, connection in enumerate(["points", "edges"]):
...     pl.subplot(0, i)
...     pl.view_xy()
...     _ = pl.add_title(
...         f"{connection.capitalize()} neighbors",
...         color="red",
...         shadow=True,
...         font_size=8,
...     )
...
...     # Add current cell
...     i_cell = 0
...     current_cell = mesh.extract_cells(i_cell)
...     _ = pl.add_mesh(
...         current_cell, show_edges=True, color="blue"
...     )
...     _ = add_point_labels(
...         current_cell.cell_centers().points,
...         labels=[f"{i_cell}"],
...     )
...
...     # Add neighbors
...     ids = mesh.cell_neighbors(i_cell, connection)
...     cells = mesh.extract_cells(ids)
...     _ = pl.add_mesh(cells, color="red", show_edges=True)
...     _ = add_point_labels(
...         cells.cell_centers().points,
...         labels=[f"{i}" for i in ids],
...     )
...
...     # Add other cells
...     ids.append(i_cell)
...     others = mesh.extract_cells(ids, invert=True)
...     _ = pl.add_mesh(others, show_edges=True)
...
>>> pl.show()

Static Scene

Interactive Scene