### 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 ($$\delta$$):

$\sqrt{\sum_i (V_i-U_i)^2} < \delta$

### 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.