Using a column vector of indices to replace values in a matrix

31 views (last 30 days)
Teddy Fisher
Teddy Fisher on 13 Dec 2019
Commented: sruizpp on 18 Nov 2020
Hello,
I have a column vector, C, (55x1 double) which are the indices of my values of interest in Matrix, M which is 370x29 double.
I want to replace all the values in M that are not these values of interest with 0.
I am trying to use C to index into M and replace ~C with 0.
However when I try
M(~C)=0
all it does is change all the values in M to just different values and I'm not sure why.
When I try to create a new Matrix
N=M(~C==0) it returns a columnn vector with just the first 55 values in the first column of M.
Does anyone know how I can replace all the elements in M that are not listed in C with 0? I want my output to be another 370x29 double matrix.
Thanks!
  3 Comments
Fangjun Jiang
Fangjun Jiang on 13 Dec 2019
with this comments, the answer below should provide one solution.

Sign in to comment.

Accepted Answer

More Answers (1)

Guillaume
Guillaume on 13 Dec 2019
Edited: Guillaume on 13 Dec 2019
Well, now you have explained how you got C, a much simpler method than the accepted one is not to create C and use:
M(~R) = 0; %that's all that is needed!
As usual in matlab, find is completely unnecessary and what you were trying to do initially would have worked had you kept your original logical vector.

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by