how to multiply matrix with vector n times?

1 次查看（过去 30 天）

janny 2014-11-11

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/162195-how-to-multiply-matrix-with-vector-n-times

评论： janny 2014-11-12

hi guys i have this code:

M =[0 1 0 0 0 0 0 0;0 0 1 0 0 0 0 0;0 0 0 1 0 0 0 0;0 0 0 0 1 0 0 0; 0 0 0 0 0 1 0 0;0 0 0 0 0 0 1 0;0 0 0 0 0 0 0 1;1 1 0 0 0 0 0 0];

A = [ 1 0 0 0 0 0 0 0];

C =mod((A*M'),2) % multiplication by module 2

i want to repeat the C =mod((A*M'),2) many times until one of the results repeated. how to do this?

1 个评论
显示 -1更早的评论隐藏 -1更早的评论

Roger Stafford 2014-11-11

When you say "repeated" do you mean successive vectors, C, are the same, or do you mean that one of the C's along the line is the same as some earlier C so that a cycle is created? The first meaning is easier to accomplish and the second sounds more likely.

请先登录，再进行评论。

请先登录，再回答此问题。

采纳的回答

Guillaume 2014-11-11

1
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/162195-how-to-multiply-matrix-with-vector-n-times#answer_158497

在 MATLAB Online 中打开

I assume you mean you want to repeat

A = mod(A*M', 2);

Otherwise, if A and M never changes C = mod(A*M', 2) will always give the same result!

Assuming you want to stop when any of the A that's been generated reappers again, build a matrix of A (concatenate rows) and use ismember(..., 'rows') to find if your new A is present in the matrix:

M =[0 1 0 0 0 0 0 0;0 0 1 0 0 0 0 0;0 0 0 1 0 0 0 0;0 0 0 0 1 0 0 0; 0 0 0 0 0 1 0 0;0 0 0 0 0 0 1 0;0 0 0 0 0 0 0 1;1 1 0 0 0 0 0 0];
A = [ 1 0 0 0 0 0 0 0];
AA = A;
A = mod(A*M', 2)
while ~any(ismember(A, AA, 'rows'))
  AA = [AA; A];
  A = mod(A*M', 2);
end