`nearestNeighbor`

Nearest vertex of a triangulation or alpha shape to each query point.

Category: Mathematics > Computational Geometry

Syntax

k = nearestNeighbor(TR, P)

Index of the closest vertex of the triangulation for each row of P.

[k, d] = nearestNeighbor(TR, P)

Also returns the distances.

k = nearestNeighbor(shp, xq, yq)

For an alphaShape, the closest of its points to the query points.

Description

The answer is always a vertex of the object, never a point on an edge or inside a face. The search uses Euclidean distance. For plain arrays of points use dsearchn, which works the same way.

Input arguments

TR: A triangulation, delaunayTriangulation or DelaunayTri object.
P: Query points, one per row.
shp, xq, yq: An alphaShape and the coordinates of the query points.

Output arguments

k: Indices of the nearest points, a column vector.
d: Euclidean distances to those points, a column vector.

Example

Closest vertices

x = [0 1 1 0 0.5]';
y = [0 0 1 1 0.5]';
DT = delaunayTriangulation(x, y);
[k, d] = nearestNeighbor(DT, [0.1 0.1; 0.9 0.9])

Output

nearestNeighbor