function d=rDet(A)

[a,b]=size(A);
if a~=b
    error('Matrix must be square.');
end
if a==1
    d=A; return;
end
m=1; x=0;
for n=1:b
    c=1;
    for k=1:a
        if k ~= m
            B(c,:)=[A(k,1:(n-1)), A(k,(n+1):b)];
            c=c+1;
        end
    end
    if size(B)==[2 2]
        x=A(m,n)*((-1)^(m+n)*(B(1,1)*B(2, 2)-B(2, 1)*B(1, 2)))+x;
    else
%      error('Matrix must be 3x3 or smaller');
       x=A(m,n)*((-1)^(m+n)*rDet(B))+x;
    end
end
d=x;
return;