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## -*- texinfo -*-
## @deftypefn {} {@var{r} =} spones (@var{S})
## Replace the nonzero entries of @var{S} with ones.
##
## This creates a sparse matrix with the same structure as @var{S}.
## @seealso{sparse, sprand, sprandn, sprandsym, spfun, spy}
## @end deftypefn

function r = spones (S)

  if (nargin < 1)
    print_usage ();
  endif

  [i, j, v] = find (S);
  [m, n] = size (S);

  r = sparse (i, j, 1, m, n);

endfunction


%!assert (issparse (spones ([1,2;3,0])))
%!assert (spones ([1,2;3,0]), sparse ([1,1;1,0]))
%!assert (spones (sparse ([1,2;3,0])), sparse ([1,1;1,0]))
