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

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

Answer 1

[Akira Agata]

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);

[Benson Gou]

@Akira, Thanks a lot for your valuable suggestions. Your methods work very well. Benson.