Use indices from MAX(A,[],dim) to get sum over only part of another array B
1 view (last 30 days)
Show older comments
Suppose A and B are X x Y x Z arrays, with the 3rd dimension being vertical height. I want to determine where, vertically, A falls below a threshold. Then, I want to do a vertical sum in B ONLY below that height. Currently:
X = 14; Y = 28; Z = 10;
A=rand(X,Y,Z); B=rand(X,Y,Z);
threshold=mean(A(:));
[~,I] = max(A < threshold ,[],3);
I = squeeze(I); % I now has dimensions X x Y
for i = 1:size(I,1)
for j = 1:size(I,2)
result(i,j) = nansum(B(i,j,1:I(i,j)),3);
end
end
The loop is extremely slow when this method is implemented for very large datasets. There must be a way to vectorize this code! Thank you in advance.
Edit: the process for finding I works well. It is only the loop that needs to be improved.
2 Comments
Answers (0)
See Also
Categories
Find more on Loops and Conditional Statements in Help Center and File Exchange
Products
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!