[Octave-cvsupdate] SF.net SVN: octave:[9421] trunk/octave-forge/main/signal/inst/xcorr2.m

[<car...@us...>]

Revision: 9421
          http://octave.svn.sourceforge.net/octave/?rev=9421&view=rev
Author:   carandraug
Date:     2011-12-17 00:55:16 +0000 (Sat, 17 Dec 2011)
Log Message:
-----------
xcorr2:
  * simpler input check and default setting
  * remove ancient functions warn_empty_list_elements and empty_list_elements_ok
  * help text to texinfo
  * update GPL version

Modified Paths:
--------------
    trunk/octave-forge/main/signal/inst/xcorr2.m

Modified: trunk/octave-forge/main/signal/inst/xcorr2.m
===================================================================
--- trunk/octave-forge/main/signal/inst/xcorr2.m	2011-12-16 23:21:53 UTC (rev 9420)
+++ trunk/octave-forge/main/signal/inst/xcorr2.m	2011-12-17 00:55:16 UTC (rev 9421)
@@ -1,8 +1,9 @@
 ## Copyright (C) 2000 Dave Cogdell <cog...@as...>
+## Copyright (C) 2000 Paul Kienzle <pki...@us...>
 ##
 ## 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
+## 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,
@@ -13,46 +14,49 @@
 ## You should have received a copy of the GNU General Public License
 ## along with this program; If not, see <http://www.gnu.org/licenses/>.
 
-## C = xcorr2 (A, B)
-##	Compute the 2D cross-correlation of matrices A and B.
-## C = xcorr2 (A)
-##      Compute two-dimensional autocorrelation of matrix A.
-## C = xcorr2 (..., 'scale')
-##      biased   - scales the raw cross-correlation by the maximum number
-##                 of elements of A and B involved in the generation of 
-##                 any element of C
-##      unbiased - scales the raw correlation by dividing each element 
-##                 in the cross-correlation matrix by the number of
-##                 products A and B used to generate that element 
-##      coeff    - normalizes the sequence so that the largest 
-##                 cross-correlation element is identically 1.0.
-##      none     - no scaling (this is the default).
+## -*- texinfo -*-
+## @deftypefn {Function File} {@var{c} =} xcorr2 (@var{a})
+## @deftypefnx {Function File} {@var{c} =} xcorr2 (@var{a}, @var{b})
+## @deftypefnx {Function File} {@var{c} =} xcorr2 (@dots{}, @var{scale})
+## Compute the 2D cross-correlation of matrices @var{a} and @var{b}.
+##
+## If @var{b} is not specified, it defaults to the same matrix as @var{a}, i.e.,
+## it's the same as @code{xcorr(@var{a}, @var{a})}.
+##
+## The optional argument @var{scale}, defines the type of scaling applied to the
+## cross-correlation matrix (defaults to "none"). Possible values are:
+## @itemize @bullet
+## @item "biased"
+##
+## Scales the raw cross-correlation by the maximum number of elements of @var{a}
+## and @var{b} involved in the generation of any element of @var{c}.
+##
+## @item "unbiased"
+##
+## Scales the raw correlation by dividing each element in the cross-correlation
+## matrix by the number of products @var{a} and @var{b} used to generate that
+## element 
+##
+## @item "coeff"
+##
+## Normalizes the sequence so that the largest cross-correlation element is
+## identically 1.0.
+##
+## @item "none"
+##
+## No scaling (this is the default).
+## @end itemize
+## @seealso{conv2, corr2, xcorr}
+## @end deftypefn
 
-## Author: Dave Cogdell <cog...@as...>
-## 2000-05-02 Paul Kienzle <pki...@us...>
-##    * joined R. Johnson's xcorr2f.m and Dave Cogdell's xcorr2x.m
-##    * adapted for Octave
-## 2001-01-15 Paul Kienzle
-##    * vectorized code for 'unbiased' correction
-## 2001-02-06 Paul Kienzle
-##    * replaced R. Johnson's xcorr2f code with code based on conv2
+function c = xcorr2 (a, b = a, biasflag = "none")
 
-function c = xcorr2(a,b,biasflag)
-
   if (nargin < 1 || nargin > 3)
-    usage ("c = xcorr2(A [, B] [, 'scale'])");
+    print_usage;
+  elseif (nargin == 2 && ischar (b))
+    biasflag = b;
+    b        = a;
   endif
-  if nargin == 1
-    b = a; 
-    biasflag = 'none'; 
-  elseif nargin == 2
-    if ischar (b) 
-      biasflag = b; 
-      b = a;
-    else 
-      biasflag = 'none';
-    endif
-  endif
 
   ## compute correlation
   [ma,na] = size(a);
@@ -64,26 +68,20 @@
   if strcmp(lower(biasflag), 'biased'),
     c = c / ( min ([ma, mb]) * min ([na, nb]) );
   elseif strcmp(lower(biasflag), 'unbiased'), 
-    try eleo = empty_list_elements_ok;
-    catch eleo = 0;
-    end
-    try wele = warn_empty_list_elements;
-    catch wele = 0;
-    end
-    unwind_protect
-      empty_list_elements_ok = 1;
-      warn_empty_list_elements = 0;
-      lo = min ([na,nb]); hi = max ([na, nb]);
-      row = [ 1:(lo-1), lo*ones(1,hi-lo+1), (lo-1):-1:1 ];
-      lo = min ([ma,mb]); hi = max ([ma, mb]);
-      col = [ 1:(lo-1), lo*ones(1,hi-lo+1), (lo-1):-1:1 ]';
-    unwind_protect_cleanup
-      empty_list_elements_ok = eleo;
-      warn_empty_list_elements = wele;
-    end_unwind_protect
+    lo   = min ([na,nb]);
+    hi   = max ([na, nb]);
+    row  = [ 1:(lo-1), lo*ones(1,hi-lo+1), (lo-1):-1:1 ];
+
+    lo   = min ([ma,mb]);
+    hi   = max ([ma, mb]);
+    col  = [ 1:(lo-1), lo*ones(1,hi-lo+1), (lo-1):-1:1 ]';
+
     bias = col*row;
-    c = c./bias;
+    c    = c./bias;
+
   elseif strcmp(lower(biasflag),'coeff'),
     c = c/max(c(:))';
+  else
+    error ("invalid type of scale %s", biasflag);
   endif
 endfunction

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