Set matrix element to zero for some condition
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Hello,
I'm new to Matlab and have a simple question. I have a matrix M of numbers and I like to create a new matrix, where all elements are set to zero that do not satisfy a certain condition (say, e.g., all elements larger than 1). How do I do this in the most efficient way?
I tried
filter = find((M<=1));
Mnew = M(filter);
but unfortunately it doesn't work because filter gives me a list of linear indices, but I like to keep the shape of the matrix M. I know that
[row,col] = find((M<=1));
gives me the row and column indices separately, but
Mnew = M([row,col]);
also does not do the job (I kind of understand that it does not work, but I have no idea how to fix it).
Any help is greatly appreciated!
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Accepted Answer
Vilém Frynta
on 1 Jun 2023
Edited: Vilém Frynta
on 1 Jun 2023
Hi,
my approach would be as follows:
% Matrix 5x5 with random numbers 0-10
M = randi(10, 5)
% Create logical vector of numbers higher than 5 (condition)
idx = M > 5;
% Apply it to your matrix and set those values to 0
M(idx) = 0
Ultimately, you can do it in one line.
M(M>5)=0;
2 Comments
Vilém Frynta
on 1 Jun 2023
Yes, in MATLAB, there's always simpler solution to the problem than you have. Almost always when I help people on this forum, someone better comes and does something I recommended much easier.
Happy I helped.
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