Finding the determinant without det(a)

Question

Ryan Driver 2022-1-27

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1637285-finding-the-determinant-without-det-a

编辑： DGM 2022-1-27

I need to physically computate the determinant of 3x3 matrices and lower without using the det(a) function, rather loops. What's causing this error?

1 个评论
显示 -1更早的评论隐藏 -1更早的评论

DGM 2022-1-27

编辑：DGM 2022-1-27

在 MATLAB Online 中打开

Like Max, I'm guessing that matrix a1 isn't the expected size. In the future, it's best to post the code as formatted code instead of pictures so that people can troubleshoot it.

I'm just going to throw this out there. You can reuse the code for calculating the 2x2 case.

A = rand(3);
DA1 = det(A)
DA1 = 0.0476
DA2 = det33(A)
DA2 = 0.0476
function D = det22(A)
    D = prod(A([1 4])) - prod(A([2 3]));
end
function D = det33(A)
    D = A(1,1)*det22(A(2:3,2:3)) - A(1,2)*det22(A(2:3,[1 3])) + A(1,3)*det22(A(2:3,1:2));
end	