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## Copyright (C) 2007-2013 David Bateman
##
## This file is part of Octave.
##
## Octave is free software; you can redistribute it and/or modify it
## under the terms of the GNU General Public License as published by
## the Free Software Foundation; either version 3 of the License, or (at
## your option) any later version.
##
## Octave is distributed in the hope that it will be useful, but
## WITHOUT ANY WARRANTY; without even the implied warranty of
## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
## General Public License for more details.
##
## You should have received a copy of the GNU General Public License
## along with Octave; see the file COPYING. If not, see
## <http://www.gnu.org/licenses/>.
## -*- texinfo -*-
## @deftypefn {Function File} {} swapbytes (@var{x})
## Swap the byte order on values, converting from little endian to big
## endian and vice versa. For example:
##
## @example
## @group
## swapbytes (uint16 (1:4))
## @result{} [ 256 512 768 1024]
## @end group
## @end example
##
## @seealso{typecast, cast}
## @end deftypefn
function y = swapbytes (x)
if (nargin != 1)
print_usage ();
endif
clx = class (x);
if (strcmp (clx, "int8") || strcmp (clx, "uint8") || isempty (x))
y = x;
else
if (strcmp (clx, "int16") || strcmp (clx, "uint16"))
nb = 2;
elseif (strcmp (clx, "int32") || strcmp (clx, "uint32"))
nb = 4;
elseif (strcmp (clx, "int64") || strcmp (clx, "uint64")
|| strcmp (clx, "double"))
nb = 8;
else
error ("swapbytes: invalid class of object");
endif
y = reshape (typecast (reshape (typecast (x(:), "uint8"), nb, numel (x))
([nb : -1 : 1], :) (:), clx), size (x));
endif
endfunction
%!assert (double (swapbytes (uint16 (1:4))), [256 512 768 1024])
%!error (swapbytes ())
%!error (swapbytes (1, 2))
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