Add a useful package (from Source forge) for octave

[CreaPhase.git] / octave_packages / signal-1.1.3 / upsample.m

diff --git a/octave_packages/signal-1.1.3/upsample.m b/octave_packages/signal-1.1.3/upsample.m
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+## Author: Paul Kienzle <pkienzle@users.sf.net> (2007)
+## This program is granted to the public domain.
+
+## -*- texinfo -*-
+## @deftypefn {Function File} {@var{y} =} upsample (@var{x}, @var{n})
+## @deftypefnx {Function File} {@var{y} =} upsample (@var{x}, @var{n}, @var{offset})
+## Upsample the signal, inserting n-1 zeros between every element.
+##
+## If @var{x} is a matrix, upsample every column.
+##
+## If @var{offset} is specified, control the position of the inserted sample in
+## the block of n zeros.
+## @seealso{decimate, downsample, interp, resample, upfirdn}
+## @end deftypefn
+
+function y = upsample (x, n, phase = 0)
+  if nargin<2 || nargin>3, print_usage; 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 + 1:n:end) = x;
+    if nr==1, y = y.'; end
+  else
+    y = zeros(n*nr,nc);
+    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],2,1),[0,2,0,4]);
+%!assert(upsample([3,4;7,8],2,1),[0,0;3,4;0,0;7,8]);