### Syntax

`[Mu, firstIdx] = sw_uniquetol(M,tol)`

### Description

`[Mu, firstIdx] = sw_uniquetol(m,tol)`

returns unique column vectors
within the given `tol`

tolerance. Two column vectors are considered
unequal, if the distance between them is larger than the tolerance
(\(\delta\)):

### Input Arguments

`M`

- Matrix that contains column vectors.
`tol`

- Distance tolerance, default value is \(10^{-5}\).

### Output Arguments

`Mu`

- Matrix that contains the unique column vectors.
`firstIdx`

- Indices pointing to the first occurence of the unique element.

This function is similar to the Matlab built-in
`unique(M,'rows','first')`

, but with controllable tolerance.