issingular.m

来自「多小波图像压缩处理」· M 代码 · 共 23 行

function yesno = issingular(S)


[n1,n2,n3] = size(S);
if (n1 ~= n2 | n3 > 1)
    yesno = 1;
    return
end

% try to simplify first
n = size(S);
S = reshape(simplify(S(:)),n);
try 
    S = double(S);
    yesno = iszero(det(S));
catch
% if S contains symbolic variables without numerical values,
% the conversion to "double" will fail. Then we end up here.
% We do the same thing, except this time the determinant
% is symbolic
    yesno = iszero(simplify(det(S)));
end