Mercurial > octave-nkf
view scripts/polynomial/polyder.m @ 20584:eb9e2d187ed2
maint: Use Octave coding conventions in scripts/ode/private dir.
* AbsRel_Norm.m, fuzzy_compare.m, hermite_quartic_interpolation.m,
integrate_adaptive.m, integrate_const.m, integrate_n_steps.m, kahan.m,
ode_struct_value_check.m, odepkg_event_handle.m, odepkg_structure_check.m,
runge_kutta_45_dorpri.m, starting_stepsize.m:
Wrap long lines to < 80 chars.
Use double quotes rather than single quotes where possible.
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Use '##" for stand-alone comments and '#' for end-of-line comments.
Use two spaces after period before starting new sentence.
Use '!' instead of '~' for logical negation.
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author | Rik <rik@octave.org> |
---|---|
date | Sun, 04 Oct 2015 22:18:54 -0700 |
parents | 83792dd9bcc1 |
children |
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## Copyright (C) 1994-2015 John W. Eaton ## ## 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 ## <http://www.gnu.org/licenses/>. ## -*- texinfo -*- ## @deftypefn {Function File} {} polyder (@var{p}) ## @deftypefnx {Function File} {[@var{k}] =} polyder (@var{a}, @var{b}) ## @deftypefnx {Function File} {[@var{q}, @var{d}] =} polyder (@var{b}, @var{a}) ## Return the coefficients of the derivative of the polynomial whose ## coefficients are given by the vector @var{p}. ## ## If a pair of polynomials is given, return the derivative of the product ## @math{@var{a}*@var{b}}. ## ## If two inputs and two outputs are given, return the derivative of the ## polynomial quotient @math{@var{b}/@var{a}}. The quotient numerator is ## in @var{q} and the denominator in @var{d}. ## @seealso{polyint, polyval, polyreduce} ## @end deftypefn ## Author: Tony Richardson <arichard@stark.cc.oh.us> ## Created: June 1994 ## Adapted-By: jwe function [q, d] = polyder (p, a) if (nargin == 1 || nargin == 2) if (! isvector (p)) error ("polyder: argument must be a vector"); endif if (nargin == 2) if (! isvector (a)) error ("polyder: argument must be a vector"); endif if (nargout == 1) ## derivative of p*a returns a single polynomial q = polyder (conv (p, a)); else ## derivative of p/a returns numerator and denominator d = conv (a, a); if (numel (p) == 1) q = -p * polyder (a); elseif (numel (a) == 1) q = a * polyder (p); else q = conv (polyder (p), a) - conv (p, polyder (a)); q = polyreduce (q); endif ## remove common factors from numerator and denominator x = polygcd (q, d); if (length (x) != 1) q = deconv (q, x); d = deconv (d, x); endif ## move all the gain into the numerator q /= d(1); d /= d(1); endif else lp = numel (p); if (lp == 1) q = 0; return; elseif (lp == 0) q = []; return; endif ## Force P to be a row vector. p = p(:).'; q = p(1:(lp-1)) .* [(lp-1):-1:1]; endif else print_usage (); endif endfunction %!assert (polyder ([1, 2, 3], [2, 2])) %!assert (polyder (13), 0) %!error polyder ([]) %!error polyder (1,2,3) %!error <argument must be a vector> polyder ([1, 2; 3, 4])