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How to multiply special elements
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Hi,
I am a new with Matlab and I need some help. I need to multiply by (-1) all the elements that their row is even and their column is odd or their row is odd and their column is even. How can I do that?
Thanks you in advance
3 Comments
Image Analyst
on 7 Nov 2014
If this is a homework problem you should have Tagged it as homework below. If so, tag it and read this.
Answers (2)
Chad Greene
on 7 Nov 2014
Here's one way:
A = magic(5)
[cols,rows] = meshgrid(1:size(A,1),1:size(A,2));
A(mod(rows,2)==0&mod(cols,2)==1 | mod(cols,2)==0&mod(rows,2)==1)=-A(mod(rows,2)==0&mod(cols,2)==1 |mod(cols,2)==0&mod(rows,2)==1)
1 Comment
Image Analyst
on 7 Nov 2014
Simply use numel and linear indexing:
m=randi(255, 5, 6) % Create sample data.
indexesToInvert = 2 : 2 : numel(m);
m(indexesToInvert) = -m(indexesToInvert)
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