Delete columns of a matrix based on values in other matrix
2 views (last 30 days)
Show older comments
I have 3 matrices. The 2nd column of Matrix #1 counts up from 1 to 200. I want to check the 4th column of matrix #2 and the 10th column of matrix #3. If Matrix #1 contains a value in col2 that matrix 2 col4 or matrix 3 col10 does not have, i want to delete or turn the whole row containing that uncommon values to zeros.
Ex.
Matrix 1 (col2) Matrix 2 (col4) Matrix 3 (col10)
1 2 1
2 3 2
3 4 3
4 5 4
5 7 5
6 8 7
7 9 9
8 10 10
9 11 11
10 12 12
...
In this case, i am looking for rows 1, 6 and 8 to be deleted(or turned to zeros) from Matrix 1. Row 6 of Matrix 2 and row 1 of matrix 3.
Thanks
0 Comments
Accepted Answer
Adam Danz
on 22 Jul 2019
Edited: Adam Danz
on 22 Jul 2019
Replaces identified rows with zeros.
% Example data that match the indices in your question
M1 = rand(10,10); M1(:,2) = 1:10;
M2 = rand(10,10); M2(:,4) = [2:5,7:12];
M3 = rand(10,10); M3(:,10) = [1:5,7,9:12];
% Identify rows that should be eliminated; replace data with zeros.
idx = ~ismember(M1(:,2),M2(:,4)) | ~ismember(M1(:,2),M3(:,10));
M1(idx,:) = 0;
Note that row 6 should also be altered in addition to row 1 and 8.
If you'd rather delete those rows in M1 rather than replace the values with 0s,
M1(idx,:) = [];
4 Comments
More Answers (0)
See Also
Categories
Find more on Matrix Indexing in Help Center and File Exchange
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!