How to sum specific elements in a row of a matrix
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Ashton Linney
on 27 Mar 2020
Commented: Ashton Linney
on 27 Mar 2020
I have a 256 by 256 matrix, lets say it is called m.
I would like to sum specific elements from a specific row in that matrix.
For example, just looking at row 1, I would like to sum the following of these elements:
1-4, (multiples of 16) + 1, (multiples of 16) + 2, (multiples of 16) + 3, and (multiples of 16) + 4.
Therefore I will end up with a single value for each row of the matrix.
Please can somebody help me with the coding for this?
Thank you
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Accepted Answer
Ameer Hamza
on 27 Mar 2020
Try this:
m = rand(256,256);
mask = reshape((1:16:256)+(0:3)', 1, []);
result = sum(m(:,mask), 2);
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