X-Git-Url: https://git.creatis.insa-lyon.fr/pubgit/?p=CreaPhase.git;a=blobdiff_plain;f=octave_packages%2Fcommunications-1.1.1%2Fshannonfanoenco.m;fp=octave_packages%2Fcommunications-1.1.1%2Fshannonfanoenco.m;h=9e528f380c8a2932458443ddd58c89b850d42a8f;hp=0000000000000000000000000000000000000000;hb=c880e8788dfc484bf23ce13fa2787f2c6bca4863;hpb=1705066eceaaea976f010f669ce8e972f3734b05 diff --git a/octave_packages/communications-1.1.1/shannonfanoenco.m b/octave_packages/communications-1.1.1/shannonfanoenco.m new file mode 100644 index 0000000..9e528f3 --- /dev/null +++ b/octave_packages/communications-1.1.1/shannonfanoenco.m @@ -0,0 +1,50 @@ +## Copyright (C) 2006 Muthiah Annamalai +## +## 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 . + +## -*- texinfo -*- +## @deftypefn {Function File} {} shannonfanoenco (@var{hcode},@var{dict}) +## +## Returns the Shannon Fano encoded signal using @var{dict}. +## This function uses a @var{dict} built from the @code{shannonfanodict} +## and uses it to encode a signal list into a shannon fano code. +## Restrictions include a signal set that strictly belongs in the +## @code{range [1,N]} with @code{N=length(dict)}. Also dict can only be +## from the @code{shannonfanodict()} routine. +## An example use of @code{shannonfanoenco} is +## +## @example +## @group +## hd=shannonfanodict(1:4,[0.5 0.25 0.15 0.10]) +## shannonfanoenco(1:4,hd) # [ 0 1 0 1 1 0 1 1 1 0] +## @end group +## @end example +## @end deftypefn +## @seealso{shannonfanodeco, shannonfanodict} +## + +function sf_code=shannonfanoenco(sig,dict) + if nargin < 2 + error('usage: huffmanenco(sig,dict)'); + end + if (max(sig) > length(dict)) || ( min(sig) < 1) + error("signal has elements that are outside alphabet set ... + Cannot encode."); + end + sf_code=[dict{sig}]; + return +end +%! +%! assert(shannonfanoenco(1:4, shannonfanodict(1:4,[0.5 0.25 0.15 0.10])),[ 0 1 0 1 1 0 1 1 1 0],0) +%!