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## -*- texinfo -*-
## @deftypefn  {} {} pow2 (@var{x})
## @deftypefnx {} {} pow2 (@var{f}, @var{e})
## With one input argument, compute
## @tex
## $2^x$
## @end tex
## @ifnottex
## 2 .^ x
## @end ifnottex
## for each element of @var{x}.
##
## With two input arguments, return
## @tex
## $f \cdot 2^e$.
## @end tex
## @ifnottex
## f .* (2 .^ e).
## @end ifnottex
## @seealso{log2, nextpow2, power}
## @end deftypefn

function y = pow2 (f, e)

  if (nargin < 1)
    print_usage ();
  endif

  if (nargin == 1)
    y = 2 .^ f;
  else
    y = f .* (2 .^ e);
  endif

endfunction


%!test
%! x = [3, 0, -3];
%! v = [8, 1, .125];
%! assert (pow2 (x), v, sqrt (eps));

%!test
%! x = [3, 0, -3, 4, 0, -4, 5, 0, -5];
%! y = [-2, -2, -2, 1, 1, 1, 3, 3, 3];
%! z = x .* (2 .^ y);
%! assert (pow2 (x,y), z, sqrt (eps));

%!error <Invalid call> pow2 ()