MATLAB Function Reference |

N-dimensional nearest point search

**Syntax**

**Description**

```
k = dsearchn(X,T,XI)
```

returns the indices `k`

of the closest points in `X`

for each point in `XI`

. `X`

is an `m`

-by-`n`

matrix representing `m`

points in n-dimensional space. `XI`

is a `p`

-by-`n`

matrix, representing `p`

points in n-dimensional space. `T`

is a `numt`

-by-`n+1`

matrix, a tessellation of the data `X`

generated by `delaunayn`

. The output `k`

is a column vector of length `p`

.

```
k = dsearchn(X,T,XI,outval)
```

returns the indices `k`

of the closest points in `X`

for each point in `XI`

, unless a point is outside the convex hull. If `XI(J,:)`

is outside the convex hull, then `K(J)`

is assigned `outval`

, a scalar double. `Inf`

is often used for `outval`

. If `outval`

is `[]`

, then `k`

is the same as in the case `k = dsearchn(X,T,XI)`

.

```
k = dsearchn(X,XI)
```

performs the search without using a tessellation. With large `X`

and small `XI`

, this approach is faster and uses much less memory.

```
[k,d] = dsearchn(X,...)
```

also returns the distances `d`

to the closest points. `d`

is a column vector of length `p`

.

**See Also**

`tsearch`

, `dsearch`

, `tsearchn`

, `griddatan`

, `delaunayn`

dsearch | echo |

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