cleans matrices (round to zero small entries)
B=clean(A [,epsa [,epsr]])
:A a numerical matrix (scalar, polynomial, sparse...) : :epsa,epsr real numbers. Cleaning tolerances (default values resp.
1.d-10 and 1.d-10)
:
This function eliminates (i.e. set to zero) all the coefficients with absolute value < epsa or 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.
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))