determ

Arguments

W

real square polynomial matrix

k

integer (upper bound for the degree of the determinant of W)

Description

returns the determinant of a real polynomial matrix (computation made by FFT if W size is greater than 2*2).

res=determ(W [,k])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*max(degree(W)).

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.

Examples

s=poly(0,'s');
w=s*rand(10,10);
determ(w)
det(coeff(w,1))*s^10

See Also

• det — determinant
• detr — polynomial determinant
• coffg — inverse of polynomial matrix

Authors

F.D.