determinant of polynomial matrix
real square polynomial matrix
integer (upper bound for the degree of the determinant of W)
returns the determinant of a real polynomial matrix (computation made by FFT if W size is greater than 2*2).
k is an integer larger than the actual degree of the determinant
The default value of
k is the smallest power of 2 which is larger
Method (Only if W size is greater than 2*2) : evaluate the determinant of
W for the Fourier frequencies
and apply inverse FFT to the coefficients of the determinant.