How to find the last nonzero entry in all rows of a sparse matrix?

1 view (last 30 days)
Dear All,
I need to find out the last nonzero entry in each row of a sparase matrix A. Say A=[1 3 0 0 0 0;0 4 2 3 0 0;5 0 0 1 4 0]. The location of last nonzero entry in all rows of A are [2 4 5].
Thanks a lot in advance.
Benson

Accepted Answer

Akira Agata
Akira Agata on 8 Apr 2019
How about the following?
[Solution 1]
A = [1 3 0 0 0 0;0 4 2 3 0 0;5 0 0 1 4 0];
pos = nan(size(A,1),1);
for kk = 1:size(A,1)
pos(kk) = find(A(kk,:),1,'last');
end
[Solution 2]
A = [1 3 0 0 0 0;0 4 2 3 0 0;5 0 0 1 4 0];
C = mat2cell(A,ones(1,size(A,1)));
pos = cellfun(@(x) find(x,1,'last'),C);

More Answers (0)

Categories

Find more on Sparse Matrices 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!