Mercurial > octave
view scripts/polynomial/conv.m @ 33577:2506c2d30b32 bytecode-interpreter tip
maint: Merge default to bytecode-interpreter
author | Arun Giridhar <arungiridhar@gmail.com> |
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date | Sat, 11 May 2024 18:49:01 -0400 |
parents | 2e484f9f1f18 |
children |
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######################################################################## ## ## Copyright (C) 1994-2024 The Octave Project Developers ## ## See the file COPYRIGHT.md in the top-level directory of this ## distribution or <https://octave.org/copyright/>. ## ## This file is part of Octave. ## ## Octave 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. ## ## Octave 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 Octave; see the file COPYING. If not, see ## <https://www.gnu.org/licenses/>. ## ######################################################################## ## -*- texinfo -*- ## @deftypefn {} {@var{y} =} conv (@var{a}, @var{b}) ## @deftypefnx {} {@var{y} =} conv (@var{a}, @var{b}, @var{shape}) ## Convolve two vectors @var{a} and @var{b}. ## ## When @var{a} and @var{b} are the coefficient vectors of two polynomials, the ## convolution represents the coefficient vector of the product polynomial. ## ## The size of the result is determined by the optional @var{shape} argument ## which takes the following values ## ## @table @asis ## @item @var{shape} = @qcode{"full"} ## Return the full convolution. (default) ## The result is a vector with length equal to ## @code{length (@var{a}) + length (@var{b}) - 1}. ## ## @item @var{shape} = @qcode{"same"} ## Return the central part of the convolution with the same size as @var{a}. ## ## @item @var{shape} = @qcode{"valid"} ## Return only the parts which do not include zero-padded edges. ## The size of the result is ## @code{max (size (@var{a}) - size (@var{b}) + 1, 0)}. ## @end table ## ## @seealso{deconv, conv2, convn, fftconv} ## @end deftypefn function y = conv (a, b, shape = "full") if (nargin < 2) print_usage (); endif if (! (isvector (a) && isvector (b))) error ("conv: both arguments A and B must be vectors"); elseif (nargin == 3 && ! any (strcmpi (shape, {"full", "same", "valid"}))) error ('conv: SHAPE argument must be "full", "same", or "valid"'); endif y = conv2 (a(:), b(:), shape); if (strcmpi (shape, "full")) ## Adapt the shape to the longest input argument, if necessary. if ((length (a) > length (b) && isrow (a)) ... || (length (a) <= length (b) && isrow (b))) y = y.'; endif elseif (isrow (a)) ## Adapt the shape to the first input argument, if necessary. y = y.'; endif endfunction %!test %! x = ones (3,1); %! y = ones (1,3); %! b = 2; %! c = 3; %! assert (conv (x, x), [1; 2; 3; 2; 1]); %! assert (conv (y, y), [1, 2, 3, 2, 1]); %! assert (conv (x, y), [1, 2, 3, 2, 1]); %! assert (conv (y, x), [1; 2; 3; 2; 1]); %! assert (conv (c, x), [3; 3; 3]); %! assert (conv (c, y), [3, 3, 3]); %! assert (conv (x, c), [3; 3; 3]); %! assert (conv (y, c), [3, 3, 3]); %! assert (conv (b, c), 6); %!shared a,b %!test %! a = 1:10; %! b = 1:3; %!assert (size (conv (a,b)), [1, numel(a)+numel(b)-1]) %!assert (size (conv (b,a)), [1, numel(a)+numel(b)-1]) %!test %! a = (1:10).'; %!assert (size (conv (a,b)), [numel(a)+numel(b)-1, 1]) %!assert (size (conv (b,a)), [numel(a)+numel(b)-1, 1]) %!test %! a = 1:10; %! b = (1:3).'; %!assert (size (conv (a,b)), [1, numel(a)+numel(b)-1]) %!assert (size (conv (b,a)), [1, numel(a)+numel(b)-1]) %!test %! a = 1:10; %! b = 1:3; %!assert (conv (a,b,"full"), conv (a,b)) %!assert (conv (b,a,"full"), conv (b,a)) %!assert (conv (a,b,"same"), [4, 10, 16, 22, 28, 34, 40, 46, 52, 47]) %!assert (conv (b,a,"same"), [28, 34, 40]) %!assert (conv (a,b,"valid"), [10, 16, 22, 28, 34, 40, 46, 52]) %!assert (conv (b,a,"valid"), zeros (1,0)) ## Test input validation %!error <Invalid call> conv (1) %!error <A and B must be vectors> conv ([1, 2; 3, 4], 3) %!error <A and B must be vectors> conv (3, [1, 2; 3, 4]) %!error <SHAPE argument must be> conv (2, 3, "INVALID_SHAPE")