Making an Array out of another Array if conditions are met

6 views (last 30 days)
Rachael Bell
Rachael Bell on 7 Jun 2022
Edited: Rachael Bell on 7 Jun 2022
Hello!
So I have a double array that is 15369x9. I am attempting to make a raster plot from this but inorder to do so i need to break the raw data array down into two different arrays, specifically one that has all of the trial starts in it( indicated by a number 1 in the 5th column) and licks(indicated by a 0 in the 5th column) I know I need to use a for loop to index through the array and I want to use an if loop to generate the new array, but I have no real idea how to do that. Any help would be greatly appreciated. Thanks!

Accepted Answer

James Tursa
James Tursa on 7 Jun 2022
Edited: James Tursa on 7 Jun 2022
You don't need a for-loop for this. The best way is to use logical indexing. See this link:
Basically, you create a logical vector with the conditions you want, and then use that to index into the variable. E.g.,
M = your matrix
M(:,5) is the 5th column of the matrix
x = M(:,5)==1 is a logical vector indicating where there is a 1 in the 5th column
M(x,:) is a subset of M where there is a 1 in column 5.
Etc.
  2 Comments
James Tursa
James Tursa on 7 Jun 2022
The method shown retains the entire rows where the column data matches your desired value. I did make an edit to my original post so be sure to grab the latest code shown.

Sign in to comment.

More Answers (0)

Tags

Community Treasure Hunt

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

Start Hunting!