Re: element extraction from vector

[Vic Norton]

Try this, Hassen, following Jaroslav's "find" technique:

  A = rand(10, 5) - ones(10, 5) * 0.5;
  A = A .* (abs(A) < 0.3);
  for j = 1 : columns(A)
    B(j).j = j;
    B(j).w = w = find(A(:, j));
    B(j).v = A(w, j);
  endfor

Now look at A and B(1), B(2), B(3), B(4), and B(5). Isn't this what you want?

Regards,

Vic

On Dec 27, 2009, at 5:09 PM, address@hidden wrote:

> Vic and Jaroslav, thank you very much.
> is it possible to do the job for a matrix X? i.e. for every column of X, we 
> obtain a vector of nonzero elements of this column and their indices in this 
> column. I remark that the function 'find' stoke the nonzero elements of the 
> matrix in a row vector so that when we look at the output, we can not have an 
> idea of the nonzero elements of each column or their indices.
> I hope that I don't disturb you.
> 
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