finding nonzero elements in matrix

Hello,

I have a matrix with the values of either zero or one; I want to find non zero elements in every coloumn and locate the indices of each non zero element in every coloumn of a new matrix. For example, let's say my original matrix looks like this:

a =

0 1 1

0 0 1

1 1 1

I want the indices of non zero element in a new matrix look like this:

b =

0 1 1

0 0 2

3 3 3

How can I do it? I tried with the find function but without any success.

Thanks in advance,

Tilek

Answer 1

[KSSV]

iwant = zeros(size(A)) ; 
for i = 1:size(A,1)
  if any(A(i,:))
    iwant(i,A(i,:)~=0) = i ;
  end  
end

Answer 2

[Steven Lord]

Use implicit expansion.

 A = [0 1 1; 0 0 1; 1 1 1];
 R = (1:size(A, 1)).';
 B = A.*R

[Tilek Zhumabek]

it also works. Thanks!

[KSSV]

+1 ...I tried without using loop....it didn't flash in my mind that time.

[KSSV]

@Tilek Zhumabek this is the best answer compared to mine. You should accept this answer.