% MATLAB FUNCTION poldet TO COMPUTE THE
% DETERMINANT OF A SQUARE POLYNOMIAL MATRIX M

% H. Kwakernaak, July, 1990


function [detM,degdetM] = poldet(M,degM)


[rM,cM] = polsize(M,degM);
if rM ~= cM
   disp('poldet: Input matrix not square');
end
N = rM;

B = eye(N); degB = 0;
for k = 1:N
    [B,degB] = polmul(B,degB,M,degM);
    d = -poltrace(B,degB)/k;
    for i = 1:N
        for l = 1:degB+1
            B(i,(l-1)*N+i) = B(i,(l-1)*N+i) + d(1,l);
        end
    end
end
[detM,degdetM] = clcoef(d,degB);