determ - determinant of polynomial matrix
returns the determinant of a real polynomial matrix (computation made by FFT).
k is an integer larger than the actual degree of the determinant of W.
The default value of k is the smallest power of 2 which is larger than n*maxi(degree(W)).
Method: evaluate the determinant of W for the Fourier frequencies and apply inverse FFT to the coefficients of the determinant.
s=poly(0,'s'); w=s*rand(10,10); determ(w) det(coeff(w,1))*s^10