--- /dev/null
+## Copyright (C) 2008 David Bateman <adb014@gmail.com>
+##
+## 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 <http://www.gnu.org/licenses/>.
+
+## -*- texinfo -*-
+## @deftypefn {Function File} {@var{y} = } buffer (@var{x}, @var{n}, @var{p}, @var{opt})
+## @deftypefnx {Function File} {[@var{y}, @var{z}, @var{opt}] = } buffer (@dots{})
+## Buffer a signal into a data frame. The arguments to @code{buffer} are
+##
+## @table @asis
+## @item @var{x}
+## The data to be buffered.
+##
+## @item @var{n}
+## The number of rows in the produced data buffer. This is an positive
+## integer value and must be supplied.
+##
+## @item @var{p}
+## An integer less than @var{n} that specifies the under- or overlap
+## between column in the data frame. The default value of @var{p} is 0.
+##
+## @item @var{opt}
+## In the case of an overlap, @var{opt} can be either a vector of length
+## @var{p} or the string 'nodelay'. If @var{opt} is a vector, then the
+## first @var{p} entries in @var{y} will be filled with these values. If
+## @var{opt} is the string 'nodelay', then the first value of @var{y}
+## corresponds to the first value of @var{x}.
+##
+## In the can of an underlap, @var{opt} must be an integer between 0 and
+## @code{-@var{p}}. The represents the initial underlap of the first
+## column of @var{y}.
+##
+## The default value for @var{opt} the vector @code{zeros (1, @var{p})}
+## in the case of an overlap, or 0 otherwise.
+## @end table
+##
+## In the case of a single output argument, @var{y} will be padded with
+## zeros to fill the missing values in the data frame. With two output
+## arguments @var{z} is the remaining data that has not been used in the
+## current data frame.
+##
+## Likewise, the output @var{opt} is the overlap, or underlap that might
+## be used for a future call to @code{code} to allow continuous buffering.
+## @end deftypefn
+
+function [y, z, opt] = buffer (x, n, p, opt)
+
+ if (nargin < 2 || nargin > 4)
+ print_usage ();
+ endif
+ if (!isscalar (n) || n != floor (n))
+ error ("buffer: n must be an inetger");
+ endif
+ if (nargin < 3)
+ p = 0;
+ elseif (!isscalar (p) || p != floor (p) || p >= n)
+ error ("buffer: p must be an inetger less than n");
+ endif
+ if (nargin < 4)
+ if (p < 0)
+ opt = 0;
+ else
+ opt = zeros (1, p);
+ endif
+ endif
+
+ if (rows (x) == 1)
+ isrowvec = true;
+ else
+ isrowvec = false;
+ endif
+
+ if (p < 0)
+ if (isscalar (opt) && opt == floor (opt) && opt >= 0 && opt <= -p)
+ lopt = opt;
+ else
+ error ("buffer: expecting fourth argument to be and integer between 0 and -p");
+ endif
+ else
+ lopt = 0;
+ endif
+
+ x = x (:);
+ l = length (x);
+ m = ceil ((l - lopt) / (n - p));
+ y = zeros (n - p, m);
+ y (1 : l - lopt) = x (lopt + 1 : end);
+ if (p < 0)
+ y (end + p + 1 : end, :) = [];
+ elseif (p > 0)
+ if (ischar (opt))
+ if (strcmp (opt, "nodelay"))
+ y = [y ; zeros(p, m)];
+ if (p > n / 2)
+ is = n - p + 1;
+ in = n - p;
+ ie = is + in - 1;
+ off = 1;
+ while (in > 0)
+ y (is : ie, 1 : end - off) = y (1 : in, 1 + off : end);
+ off++;
+ is = ie + 1;
+ ie = ie + in;
+ if (ie > n)
+ ie = n;
+ endif
+ in = ie - is + 1;
+ endwhile
+ [i, j] = ind2sub([n-p, m], l);
+ if (all ([i, j] == [n-p, m]))
+ off --;
+ endif
+ y (:, end - off + 2 : end) = [];
+ else
+ y (end - p + 1 : end, 1 : end - 1) = y (1 : p, 2 : end);
+ if (sub2ind([n-p, m], p, m) >= l)
+ y (:, end) = [];
+ endif
+ endif
+ else
+ error ("buffer: unexpected string argument");
+ endif
+ elseif (isvector (opt))
+ if (length (opt) == p)
+ lopt = p;
+ y = [zeros(p, m); y];
+ in = p;
+ off = 1;
+ while (in > 0)
+ y (1 : in, off) = opt(off:end);
+ off++;
+ in = in - n + p;
+ endwhile
+ if (p > n / 2)
+ in = n - p;
+ ie = p;
+ is = p - in + 1;
+ off = 1;
+ while (ie > 0)
+ y (is : ie, 1 + off : end) = ...
+ y (end - in + 1 : end, 1 : end - off);
+ off++;
+ ie = is - 1;
+ is = is - in;
+ if (is < 1)
+ is = 1;
+ endif
+ in = ie - is + 1;
+ endwhile
+ else
+ y (1 : p, 2 : end) = y (end - p + 1 : end, 1 : end - 1);
+ endif
+ else
+ error ("buffer: opt vector must be of length p");
+ endif
+ else
+ error ("buffer: unrecognized fourth argument");
+ endif
+ endif
+ if (nargout > 1)
+ if (p >= 0)
+ [i, j] = ind2sub (size(y), l + lopt + p * (size (y, 2) - 1));
+ if (any ([i, j] != size (y)))
+ z = y (1 + p : i, end);
+ y (:, end) = [];
+ else
+ z = zeros (0, 1);
+ endif
+ else
+ [i, j] = ind2sub (size (y) + [-p, 0], l - lopt);
+ if (i < size (y, 1))
+ z = y (1: i, end);
+ y (:, end) = [];
+ else
+ z = zeros (0, 1);
+ endif
+ endif
+ if (isrowvec)
+ z = z.';
+ endif
+ if (p < 0)
+ opt = max(0, size (y, 2) * (n - p) + opt - l);
+ elseif (p > 0)
+ opt = y(end-p+1:end)(:);
+ else
+ opt = [];
+ endif
+ endif
+endfunction
+
+%!error (buffer(1:10, 4.1))
+%!assert (buffer(1:10, 4), reshape([1:10,0,0],[4,3]))
+%!assert (buffer(1:10, 4, 1), reshape([0:3,3:6,6:9,9,10,0,0],[4,4]))
+%!assert (buffer(1:10, 4, 2), reshape ([0,0:2,1:4,3:6,5:8,7:10],[4,5]))
+%!assert (buffer(1:10, 4, 3), [0,0,0:7;0,0:8;0:9;1:10])
+%!error (buffer(1:10, 4, 3.1))
+%!error (buffer(1:10, 4, 4))
+%!assert (buffer(1:10, 4, -1), reshape([1:4,6:9],[4,2]))
+%!assert (buffer(1:10, 4, -2), reshape([1:4,7:10],[4,2]))
+%!assert (buffer(1:10, 4, -3), reshape([1:4,8:10,0],[4,2]))
+%!assert (buffer(1:10, 4, 1, 11), reshape([11,1:3,3:6,6:9,9,10,0,0],[4,4]))
+%!error (buffer(1:10, 4, 1, [10,11]))
+%!assert (buffer(1:10, 4, 1, 'nodelay'), reshape([1:4,4:7,7:10],[4,3]))
+%!error (buffer(1:10, 4, 1, 'badstring'))
+%!assert (buffer(1:10, 4, 2,'nodelay'), reshape ([1:4,3:6,5:8,7:10],[4,4]))
+%!assert (buffer(1:10, 4, 3, [11,12,13]),[11,12,13,1:7;12,13,1:8;13,1:9;1:10])
+%!assert (buffer(1:10, 4, 3, 'nodelay'),[1:8;2:9;3:10;4:10,0])
+%!assert (buffer(1:11,4,-2,1),reshape([2:5,8:11],4,2))
+
+%!test
+%! [y, z] = buffer(1:12,4);
+%! assert (y, reshape(1:12,4,3));
+%! assert (z, zeros (1,0));
+
+%!test
+%! [y, z] = buffer(1:11,4);
+%! assert (y, reshape(1:8,4,2));
+%! assert (z, [9, 10, 11]);
+
+%!test
+%! [y, z] = buffer([1:12]',4);
+%! assert (y, reshape(1:12,4,3));
+%! assert (z, zeros (0,1));
+
+%!test
+%! [y, z] = buffer([1:11]',4);
+%! assert (y, reshape(1:8,4,2));
+%! assert (z, [9; 10; 11]);
+
+%!test
+%! [y,z,opt] = buffer(1:15,4,-2,1);
+%! assert (y, reshape([2:5,8:11],4,2));
+%! assert (z, [14, 15]);
+%! assert (opt, 0);
+
+%!test
+%! [y,z,opt] = buffer(1:11,4,-2,1);
+%! assert (y, reshape([2:5,8:11],4,2));
+%! assert (z, zeros (1,0));
+%! assert (opt, 2);
+
+%!test
+%! [y,z,opt] = buffer([1:15]',4,-2,1);
+%! assert (y, reshape([2:5,8:11],4,2));
+%! assert (z, [14; 15]);
+%! assert (opt, 0);
+
+%!test
+%! [y,z,opt] = buffer([1:11]',4,-2,1);
+%! assert (y, reshape([2:5,8:11],4,2));
+%! assert (z, zeros (0, 1));
+%! assert (opt, 2);
+
+%!test
+%! [y,z,opt] = buffer([1:11],5,2,[-1,0]);
+%! assert (y, reshape ([-1:3,2:6,5:9],[5,3]));
+%! assert (z, [10, 11]);
+%! assert (opt, [8; 9]);
+
+%!test
+%! [y,z,opt] = buffer([1:11]',5,2,[-1,0]);
+%! assert (y, reshape ([-1:3,2:6,5:9],[5,3]));
+%! assert (z, [10; 11]);
+%! assert (opt, [8; 9]);
git://git.creatis.insa-lyon.fr / CreaPhase.git / blobdiff