[Octave-cvsupdate] SF.net SVN: octave:[5206] trunk/octave-forge/main/signal/inst

[<ad...@us...>]

Revision: 5206
          http://octave.svn.sourceforge.net/octave/?rev=5206&view=rev
Author:   adb014
Date:     2008-07-30 08:47:50 +0000 (Wed, 30 Jul 2008)

Log Message:
-----------
Add 1 to phase in upsample/downsample for matlab compatiblity (For Jonathan Coker)

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

Modified: trunk/octave-forge/main/signal/inst/downsample.m
===================================================================
--- trunk/octave-forge/main/signal/inst/downsample.m	2008-07-30 07:59:40 UTC (rev 5205)
+++ trunk/octave-forge/main/signal/inst/downsample.m	2008-07-30 08:47:50 UTC (rev 5206)
@@ -7,8 +7,8 @@
 ## it prefilters the high frequency components of the signal and
 ## avoids aliasing effects.
 ##
-## @deftypefnx {Function File} @var{y} = downsample(@var{x},@var{n},@var{phase})
-## Select every nth element starting at sample @var{phase}.
+## @deftypefnx {Function File} @var{y} = downsample(@var{x},@var{n},@var{offset})
+## Select every nth element starting at sample @var{offset}.
 ## @end deftypefn
 ## @seealso{decimate, interp, resample, upfirdn, upsample}
 
@@ -16,24 +16,24 @@
 ## This function is public domain
 
 function y = downsample(x,n,phase)
-  if nargin<2 || nargin>3, usage('downsample(x,n,[phase]'); end
-  if nargin==2, phase = 1; end
+  if nargin<2 || nargin>3, usage('downsample(x,n,[offset]'); end
+  if nargin==2, phase = 0; end
 
-  if phase > n
+  if phase > n - 1
     warning("This is incompatible with Matlab (phase = 0:n-1). See\
     octave-forge signal package release notes for details." )
   end
 
   if isvector(x)
-    y = x(phase:n:end);
+    y = x(phase + 1:n:end);
   else
-    y = x(phase:n:end,:);
+    y = x(phase + 1:n:end,:);
   end
 end
 
 %!assert(downsample([1,2,3,4,5],2),[1,3,5]);
 %!assert(downsample([1;2;3;4;5],2),[1;3;5]);
 %!assert(downsample([1,2;3,4;5,6;7,8;9,10],2),[1,2;5,6;9,10]);
-%!assert(downsample([1,2,3,4,5],2,2),[2,4]);
-%!assert(downsample([1,2;3,4;5,6;7,8;9,10],2,2),[3,4;7,8]);
+%!assert(downsample([1,2,3,4,5],2,1),[2,4]);
+%!assert(downsample([1,2;3,4;5,6;7,8;9,10],2,1),[3,4;7,8]);
 

Modified: trunk/octave-forge/main/signal/inst/upsample.m
===================================================================
--- trunk/octave-forge/main/signal/inst/upsample.m	2008-07-30 07:59:40 UTC (rev 5205)
+++ trunk/octave-forge/main/signal/inst/upsample.m	2008-07-30 08:47:50 UTC (rev 5206)
@@ -3,7 +3,7 @@
 ## Upsample the signal, inserting n-1 zeros between every element.  
 ## If @var{x} is a matrix, upsample every column.
 ##
-## @deftypefnx {Function File} @var{y} = upsample(@var{x},@var{n},@var{phase})
+## @deftypefnx {Function File} @var{y} = upsample(@var{x},@var{n},@var{offset})
 ## Control the position of the inserted sample in the block of n zeros.
 ## @end deftypefn
 ## @seealso{decimate, downsample, interp, resample, upfirdn}
@@ -13,22 +13,27 @@
 
 function y = upsample(x,n,phase)
   if nargin<2 || nargin>3, usage('upsample(x,n,[phase]'); end
-  if nargin==2, phase = 1; end
+  if nargin==2, phase = 0; end
 
+  if phase > n - 1
+    warning("This is incompatible with Matlab (phase = 0:n-1). See\
+    octave-forge signal package release notes for details." )
+  end
+
   [nr,nc] = size(x);
   if any([nr,nc]==1),
     y = zeros(n*nr*nc,1);
-    y(phase:n:end) = x;
+    y(phase + 1:n:end) = x;
     if nr==1, y = y.'; end
   else
     y = zeros(n*nr,nc);
-    y(phase:n:end,:) = x;
+    y(phase + 1:n:end,:) = x;
   end
 end
 
 %!assert(upsample([1,3,5],2),[1,0,3,0,5,0]);
 %!assert(upsample([1;3;5],2),[1;0;3;0;5;0]);
 %!assert(upsample([1,2;5,6;9,10],2),[1,2;0,0;5,6;0,0;9,10;0,0]);
-%!assert(upsample([2,4],2,2),[0,2,0,4]);
-%!assert(upsample([3,4;7,8],2,2),[0,0;3,4;0,0;7,8]);
+%!assert(upsample([2,4],2,1),[0,2,0,4]);
+%!assert(upsample([3,4;7,8],2,1),[0,0;3,4;0,0;7,8]);
 


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