Question
Hi Mathworks community! So I have a matrix A such as: A = [1,2,3,4,5,6,7,8,9; 5,8,6,44,8,6,8,7,3; 9,8,7,6,5,4,3,2,1] And an array b that specifies the columns I' DON´T want to make zero: b = [1,4,5,9] Getting an output such as: out = [1,0,0,4,5,0,0,0,9; 5,0,0,44,8,0,0,0,3; 9,0,0,6,5,0,0,0,1] I'm working with much bigger dimensions so, Any ideas of how to do this efficiently?
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Expert Answer
Neeta Dsouza
PhD Expert
Answered Aug 15, 2026
A = [1,2,3,4,5,6,7,8,9; 5,8,6,44,8,6,8,7,3; 9,8,7,6,5,4,3,2,1]; b = [1,4,5,9]; out = zeros(size(A)); out(:,b) = A(:,b)
out = 3×9
1 0 0 4 5 0 0 0 9 5 0 0 44 8 0 0 0 3 9 0 0 6 5 0 0 0 1
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