clean - cleans matrices (round to zero small entries)
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.
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))