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# pointLocation

Class: DelaunayTri

(Will be removed) Simplex containing specified location

 Note:   pointLocation(DelaunayTri) will be removed in a future release. Use pointLocation(triangulation) instead.DelaunayTri will be removed in a future release. Use delaunayTriangulation instead.

## Syntax

SI = pointLocation(DT,QX)
SI = pointLocation(DT,QX,QY)
SI = pointLocation(DT,QX,QY,QZ)
[SI, BC] = pointLocation(DT,...)

## Description

SI = pointLocation(DT,QX) returns the indices SI of the enclosing simplex (triangle/tetrahedron) for each query point location in QX. The enclosing simplex for point QX(k,:) is SI(k). pointLocation returns NaN for all points outside the convex hull.

SI = pointLocation(DT,QX,QY) and SI = pointLocation(DT,QX,QY,QZ) allow the query point locations to be specified in alternative column vector format when working in 2-D and 3-D.

[SI, BC] = pointLocation(DT,...) returns the barycentric coordinates BC.

## Input Arguments

 DT Delaunay triangulation. QX Matrix of size mpts-by-ndim, mpts being the number of query points.

## Output Arguments

 SI Column vector of length mpts containing the indices of the enclosing simplex for each query point. mpts is the number of query points. BC BC is a mpts-by-ndim matrix, each row BC(i,:) represents the barycentric coordinates of QX(i,:) with respect to the enclosing simplex SI(i).

## Examples

### Example 1

Create a 2-D Delaunay triangulation:

```X = rand(10,2);
dt = DelaunayTri(X);```

Find the triangles that contain specified query points:

```qrypts = [0.25 0.25; 0.5 0.5];
triids = pointLocation(dt, qrypts)```

### Example 2

Create a 3-D Delaunay triangulation:

```x = rand(10,1);
y = rand(10,1);
z = rand(10,1);
dt = DelaunayTri(x,y,z);```

Find the triangles that contain specified query points and evaluate the barycentric coordinates:

```qrypts = [0.25 0.25 0.25; 0.5 0.5 0.5];
[tetids, bcs] = pointLocation(dt, qrypts)```