how can i reshape an indexed vector
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fadams18
am 2 Nov. 2020
Kommentiert: fadams18
am 2 Nov. 2020
Hello,
I have the following problem:
Q % e.g. 300 x 300 matrix
M % e.g. 300 x 300 matrix
omega=find(Q); % omega becomes a 86567x1 vector
b= M(omega);% b is also a 86567x1 vector
Is there a way to reshape b to have the same dimension as Q?
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Ameer Hamza
am 2 Nov. 2020
Bearbeitet: Ameer Hamza
am 2 Nov. 2020
Q has 90000 elements, whereas b has 86567 elements. Direct reshaping is not possible. I guess you are trying to do something like this
Q % e.g. 300 x 300 matrix
M % e.g. 300 x 300 matrix
b = M.*Q
It an element in Q is zero, then it will multiply the corresponding element in M with 0 too.
3 Kommentare
Ameer Hamza
am 2 Nov. 2020
Ok, In that case, you can do something like this
Q = randi([0 1], 300); % e.g. 300 x 300 matrix
M = rand(300); % e.g. 300 x 300 matrix
omega=find(Q); % omega becomes a 86567x1 vector
b = M(omega);% b is also a 86567x1 vector
% apply your algorithm on b vector
B = zeros(size(Q));
B(Q~=0) = b;
B has same size as Q.
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KSSV
am 2 Nov. 2020
Whn you use find you will get the global indices in the form of column array...YOu can use logical indexing, so that you can have your matrix dimensions intact with 1 where condition is obeyed and 0 where condition is not.
omega = Q~=0;
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