how to multiply matrix with vector n times?
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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?
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Roger Stafford
2014년 11월 11일
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.
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Guillaume
2014년 11월 11일
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
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Guillaume
2014년 11월 12일
No. Try to understand what it does.
You have to replace the original
while ~any(ismember(A, AA, 'rows'))
by the four lines I've written, in the same order (well, you can swap the first two).
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