Outputting even numbers using logical indexing and rem.

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I am having troubles figuring out How can I output only the even numbers in an array using logical indexing and the rem function?
Thanks!!

Accepted Answer

Image Analyst
Image Analyst on 11 Dec 2015
Try this:
% Create sample data.
m = randi(9, 1, 20)
% Get the logical indexes of even numbers ONLY.
evenLogicalIndexes = rem(m,2) == 0;
% Extract only those even elements from m
mEven = m(evenLogicalIndexes)
  2 Comments
heehaw
heehaw on 11 Dec 2015
Oh I see now.
The rem(A,2) provides a 0 if its even and 1 if its odd. So in order to change it so its the other way around we use a logical operator == .
Thanks!!
Image Analyst
Image Analyst on 11 Dec 2015
You could also use ~ to invert it:
oddLogicalIndexes = ~rem(m,2);
Same thing. Perhaps this way is slightly faster for very large arrays.

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