/usr/share/octave/packages/communications-1.2.1/fibosplitstream.m is in octave-communications-common 1.2.1-1build1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 | ## Copyright (C) 2006 Muthiah Annamalai <muthiah.annamalai@uta.edu>
##
## This program 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.
##
## This program 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
## this program; if not, see <http://www.gnu.org/licenses/>.
## -*- texinfo -*-
## @deftypefn {Function File} {} fibosplitstream (@var{code})
##
## Returns the split data stream at the word boundaries.
## Assuming the stream was originally encoded using @code{fiboenco}
## and this routine splits the stream at the points where "11"
## occur together & gives us the code-words which
## can later be decoded from the @code{fibodeco} This however doesn't
## mean that we intend to verify if all the codewords are correct,
## and in fact the last symbol in the return list can or can not be
## a valid codeword.
##
## A example use of @code{fibosplitstream} would be
## @example
## @group
## fibodeco (fibosplitstream ([fiboenco(randint (1, 100, [0, 255]))@{:@}]))
## fibodeco (fibosplitstream ([fiboenco(1:10)@{:@}]))
## @end group
## @end example
## @seealso{fiboenco, fibodeco}
## @end deftypefn
function symbols = fibosplitstream (stream)
if (nargin != 1)
print_usage ();
endif
symbols = {};
itr = 1;
L = length (stream);
##
## Plain & Simple Algorithm. O(N)
## Walk till marker "11" or find it.
## Then split & save. A little tricky to
## handle the edge case_ without tripping over.
##
idx = [];
mark = 1;
prev_bit = stream(1);
just_decoded = 0;
for i = 2:L
if (!just_decoded && (stream(i)+prev_bit) == 2)
symbols{itr} = [stream(mark:i)];
mark = i + 1;
prev_bit = 0;
just_decoded = 1;
itr = itr+1;
else
prev_bit = stream(i);
just_decoded = 0;
endif
endfor
if (mark < L)
symbols{itr} = stream(mark:end);
endif
endfunction
%!assert (fibodeco (fibosplitstream ([fiboenco(1:10){:}])), [1:10])
%% Test input validation
%!error fibosplitstream ()
%!error fibosplitstream (1, 2)
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