clean

Scilab Function
Last update : April 1993

clean - cleans matrices (round to zero small entries)

### Calling Sequence

  `[B]=clean(A [,epsa [,epsr]])`

### Parameters

- `A` : a numerical matrix (scalar, polynomial, sparse...)
- `epsa,epsr` : real numbers (default values resp. 1.d-10 and 1.d-10)

### Description

This function eliminates (i.e. set to zero) all the coefficients with absolute value < `epsa` and relative value < `epsr` (relative means relative w.r.t. 1-norm of coefficients) in a polynomial (possibly matrix polynomial or rational matrix).

Default values are `epsa=1.d-10` and `epsr=1.d-10;`

For a constant (non polynomial) matrix `clean(A,epsa)` sets to zero all entries of `A` smaller than `epsa` .

### Examples

    x=poly(0,'x');
    w=[x,1,2+x;3+x,2-x,x^2;1,2,3+x]/3;
    w*inv(w)
    clean(w*inv(w))