########################################################################
##
## Copyright (C) 1994-2020 The Octave Project Developers
##
## See the file COPYRIGHT.md in the top-level directory of this
## distribution or <https://octave.org/copyright/>.
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########################################################################

## -*- texinfo -*-
## @deftypefn {} {} sinc (@var{x})
## Compute the sinc function.
##
## Return
## @tex
## $ \sin (\pi x)/(\pi x)$.
## @end tex
## @ifnottex
## sin (pi*x) / (pi*x).
## @end ifnottex
## @end deftypefn

function result = sinc (x)

  if (nargin != 1)
    print_usage ();
  endif

  result = ones (size (x));

  i = (x != 0);

  if (any (i(:)))
    t = pi * x(i);
    result(i) = sin (t) ./ t;
  endif

endfunction


%!assert (sinc (0), 1)
%!assert (sinc (1), 0,1e-6)
%!assert (sinc (1/2), 2/pi, 1e-6)

%!error sinc()