Spatial algorithms and data structures (scipy.spatial) — SciPy v1.15.3 Manual (original) (raw)

Spatial transformations#

These are contained in the scipy.spatial.transform submodule.

Nearest-neighbor queries#

KDTree(data[, leafsize, compact_nodes, ...]) kd-tree for quick nearest-neighbor lookup.
cKDTree(data[, leafsize, compact_nodes, ...]) kd-tree for quick nearest-neighbor lookup
Rectangle(maxes, mins) Hyperrectangle class.

Distance metrics#

Distance metrics are contained in the scipy.spatial.distance submodule.

Delaunay triangulation, convex hulls, and Voronoi diagrams#

Delaunay(points[, furthest_site, ...]) Delaunay tessellation in N dimensions.
ConvexHull(points[, incremental, qhull_options]) Convex hulls in N dimensions.
Voronoi(points[, furthest_site, ...]) Voronoi diagrams in N dimensions.
SphericalVoronoi(points[, radius, center, ...]) Voronoi diagrams on the surface of a sphere.
HalfspaceIntersection(halfspaces, interior_point) Halfspace intersections in N dimensions.

Plotting helpers#

Simplex representation#

The simplices (triangles, tetrahedra, etc.) appearing in the Delaunay tessellation (N-D simplices), convex hull facets, and Voronoi ridges (N-1-D simplices) are represented in the following scheme:

tess = Delaunay(points) hull = ConvexHull(points) voro = Voronoi(points)

coordinates of the jth vertex of the ith simplex

tess.points[tess.simplices[i, j], :] # tessellation element hull.points[hull.simplices[i, j], :] # convex hull facet voro.vertices[voro.ridge_vertices[i, j], :] # ridge between Voronoi cells

For Delaunay triangulations and convex hulls, the neighborhood structure of the simplices satisfies the condition:tess.neighbors[i,j] is the neighboring simplex of the ith simplex, opposite to the j-vertex. It is -1 in case of no neighbor.

Convex hull facets also define a hyperplane equation:

(hull.equations[i,:-1] * coord).sum() + hull.equations[i,-1] == 0

Similar hyperplane equations for the Delaunay triangulation correspond to the convex hull facets on the corresponding N+1-D paraboloid.

The Delaunay triangulation objects offer a method for locating the simplex containing a given point, and barycentric coordinate computations.

Functions#

tsearch(tri, xi) Find simplices containing the given points.
distance_matrix(x, y[, p, threshold]) Compute the distance matrix.
minkowski_distance(x, y[, p]) Compute the L**p distance between two arrays.
minkowski_distance_p(x, y[, p]) Compute the pth power of the L**p distance between two arrays.
procrustes(data1, data2) Procrustes analysis, a similarity test for two data sets.
geometric_slerp(start, end, t[, tol]) Geometric spherical linear interpolation.

Warnings / Errors used in scipy.spatial#