find index in a matrix without 'find' function

I have an array of 1000+ samples. I want to find the index of nonzero elements in a large matrix in a shortest possible time. Whats the best way to get the list of indexing without using "find" funcion?

Example

p=[0 0 .34 0; 3 0 0 3; 0 9 0 0];
v=nonzeros(p)
for i=1:length(v)
    [r,t]=find(p==v(i))
    sds{i}=[r,t];
end;

Answer 1

[Adam Danz]

find() is the quickest way to return the subscript indices of non-zero elements of a matrix but it's quicker to do so without using a loop. Is there a reason you can't use find?

p=[0 0 .34 0; 3 0 0 3; 0 9 0 0];
[rows, cols] = find(p~=0)

rows = 4×1

2 3 1 2

cols = 4×1

1 2 3 4

So, sds{i} is the same as [rows(i), cols(i)] but without repeats of the same value.