matlab小程序：求矩阵的行列式

function d = det_nXn(M)


[m, n] = size(M);


if(m ~= n)
fprintf('Error.\nMatrix must be square.\n\n');
return;
end


d = 0;


if (2 == n)
%d = det_2X2(M);
d = M(1,1) * M(2,2) - M(1,2) * M(2,1);
return;
elseif (3 == n)
%d = det_3X3(M);
d = M(1, 1) * M(2, 2) * M(3, 3) + M(2, 1) * M(3, 2) * M(1, 3) + M(1, 2) * M(2, 3) * M(3, 1) ...
- M(3, 1) * M(2, 2) * M(1, 3) - M(2, 3) * M(3, 2) * M(1, 1) - M(1, 2) * M(2, 1) * M(3, 3);
return;
else
for i = 1:n
d = d + (-1)^(i+1) * M(i, 1) * det_nXn(M([1:i-1, (i+1):n], 2:n)); 
end
end