--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main/comm/quantiz.m	Wed Oct 10 19:54:49 2001 +0000
@@ -0,0 +1,45 @@
+## Copyright (C) 2001 Paul Kienzle
+##
+## 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 2 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, write to the Free Software
+## Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+
+## qidx = quantiz(x, table)
+##   Determine position of x in strictly monotonic table.  The first
+##   interval, using index 0, corresponds to x <= table(1).
+##   Subsequent intervals are table(i-1) < x <= table(i).
+##
+## [qidx, q] = quantiz(x, table, codes)
+##   Associate each interval of the table with a code.  Use codes(1) 
+##   for x <= table(1) and codes(n+1) for table(n) < x <= table(n+1).
+##
+## [qidx, q, d] = quantiz(...)
+##   Compute distortion as mean squared distance of x from the
+##   corresponding table positions.  Note that an equally valid
+##   definition of distortion is the distance from the codebook
+##   values.
+function [qidx, q, d] = quantiz (x, table, codes)
+  if (nargin < 2 || nargin > 3)
+    usage("[qidx, q, d] = quantiz(x, table, codes)");
+  endif
+
+  qidx = length(table) - lookup(flipud(table(:)), x);
+  if (nargin > 2 && nargout > 1)
+    q = codes(qidx + 1);
+  endif
+  if (nargout > 2)
+    warning("distortion is relative to table instead of codes");
+    table = [table(1) ; table(:) ];
+    d = sumsq (x(:) - table(qidx+1)) / length(x);
+  endif
+endfunction