polydiff.m

%POLYDIFF Differentiate a polynomial
%
% PD = POLYDIFF(P) is a vector of coefficients of a polynomial (1xN-1) which is the
% derivative of the polynomial P (1xN).
%
%          p = [3 2 -1];
%          polydiff(p)
%          ans =
%              6     2
%
% See also POLYVAL.


% Copyright (C) 1993-2017, by Peter I. Corke
%
% This file is part of The Robotics Toolbox for MATLAB (RTB).
% 
% RTB is free software: you can redistribute it and/or modify
% it under the terms of the GNU Lesser General Public License as published by
% the Free Software Foundation, either version 3 of the License, or
% (at your option) any later version.
% 
% RTB 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 Lesser General Public License for more details.
% 
% You should have received a copy of the GNU Leser General Public License
% along with RTB.  If not, see <http://www.gnu.org/licenses/>.
%
% http://www.petercorke.com
function pd = polydiff(p)
	n = length(p)-1;

	pd = [n:-1:1] .* p(1:n);