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scripts/polynomial/deconv.m

changeset 10289: 4b124317dc38
parent:eb63fbe60fab
author: John W. Eaton <jwe@octave.org>
date: Tue Feb 09 20:58:55 2010 -0500 (56 minutes ago)
permissions: -rw-r--r--
description: base_properties::set_children: account for hidden children 
     1## Copyright (C) 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2002, 2004,

     2##               2005, 2006, 2007, 2008 John W. Eaton

     3##

     4## This file is part of Octave.

     5##

     6## Octave is free software; you can redistribute it and/or modify it

     7## under the terms of the GNU General Public License as published by

     8## the Free Software Foundation; either version 3 of the License, or (at

     9## your option) any later version.

    10##

    11## Octave is distributed in the hope that it will be useful, but

    12## WITHOUT ANY WARRANTY; without even the implied warranty of

    13## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

    14## General Public License for more details.

    15##

    16## You should have received a copy of the GNU General Public License

    17## along with Octave; see the file COPYING.  If not, see

    18## <http://www.gnu.org/licenses/>.

    19

    20## -*- texinfo -*-

    21## @deftypefn {Function File} {} deconv (@var{y}, @var{a})

    22## Deconvolve two vectors.

    23##

    24## @code{[b, r] = deconv (y, a)} solves for @var{b} and @var{r} such that

    25## @code{y = conv (a, b) + r}.

    26##

    27## If @var{y} and @var{a} are polynomial coefficient vectors, @var{b} will

    28## contain the coefficients of the polynomial quotient and @var{r} will be

    29## a remainder polynomial of lowest order.

    30## @seealso{conv, poly, roots, residue, polyval, polyderiv, polyint}

    31## @end deftypefn

    32

    33## Author: Tony Richardson <arichard@stark.cc.oh.us>

    34## Created: June 1994

    35## Adapted-By: jwe

    36

    37function [b, r] = deconv (y, a)

    38

    39  if (nargin != 2)

    40    print_usage ();

    41  endif

    42

    43  if (! (isvector (y) && isvector (a)))

    44    error("conv: both arguments must be vectors");

    45  endif

    46

    47  la = length (a);

    48  ly = length (y);

    49

    50  lb = ly - la + 1;

    51

    52  ## Ensure A is oriented as Y.

    53  if (diff (size (y)(1:2)) * diff (size (a)(1:2)) < 0)

    54    a = permute (a, [2, 1]);

    55  endif

    56

    57  if (ly > la)

    58    b = filter (y, a, [1, (zeros (1, ly - la))]);

    59  elseif (ly == la)

    60    b = filter (y, a, 1);

    61  else

    62    b = 0;

    63  endif

    64

    65  lc = la + length (b) - 1;

    66  if (ly == lc)

    67    r = y - conv (a, b);

    68  else

    69    ## Respect the orientation of Y"

    70    if (size (y, 1) <= size (y, 2))

    71      r = [(zeros (1, lc - ly)), y] - conv (a, b);

    72    else

    73      r = [(zeros (lc - ly, 1)); y] - conv (a, b);

    74    endif

    75    if (ly < la)

    76      ## Trim the remainder is equal to the length of Y.

    77      r = r(end-(length(y)-1):end);

    78    endif

    79  endif

    80

    81endfunction

    82

    83%!test

    84%! [b, r] = deconv ([3, 6, 9, 9], [1, 2, 3]);

    85%! assert(all (all (b == [3, 0])) && all (all (r == [0, 0, 0, 9])));

    86

    87%!test

    88%! [b, r] = deconv ([3, 6], [1, 2, 3]);

    89%! assert(b == 0 && all (all (r == [3, 6])));

    90

    91%!test

    92%! [b, r] = deconv ([3, 6], [1; 2; 3]);

    93%! assert(b == 0 && all (all (r == [3, 6])));

    94

    95%!test

    96%! [b,r] = deconv ([3; 6], [1; 2; 3]);

    97%! assert (b == 0 && all (all (r == [3; 6])))

    98

    99%!test

   100%! [b, r] = deconv ([3; 6], [1, 2, 3]);

   101%! assert (b == 0 && all (all (r == [3; 6])))

   102

   103%!error [b, r] = deconv ([3, 6], [1, 2; 3, 4]);

   104

   105%!error [b, r] = deconv ([3, 6; 1, 2], [1, 2, 3]);

   106