1 ## Copyright (C) 2007 Muthiah Annamalai <muthiah.annamalai@mavs.uta.edu>
3 ## This program is free software; you can redistribute it and/or modify it under
4 ## the terms of the GNU General Public License as published by the Free Software
5 ## Foundation; either version 3 of the License, or (at your option) any later
8 ## This program is distributed in the hope that it will be useful, but WITHOUT
9 ## ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
10 ## FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
13 ## You should have received a copy of the GNU General Public License along with
14 ## this program; if not, see <http://www.gnu.org/licenses/>.
17 ## @deftypefn {Function File} {@var{coefs}=} legendrepoly (@var{order},@var{x})
19 ## Compute the coefficients of the Legendre polynomial, given the
20 ## @var{order}. We calculate the Legendre polynomial using the recurrence
21 ## relations, Pn+1(x) = inv(n+1)*((2n+1)*x*Pn(x) - nPn-1(x)).
23 ## If the value @var{x} is specified, the polynomial is also evaluated,
24 ## otherwise just the return the coefficients of the polynomial are returned.
26 ## This is NOT the generalized Legendre polynomial.
30 function h = legendrepoly (order, val)
31 if (nargin < 1 || nargin > 2)
47 if (length(h_now) < (1+ord))
50 y=zeros(1,(1+ord)-length(h_prev));
53 h=((2*ord -1).*p1 -(ord -1).*p3)./(ord);