function [legendreP]=calc_legendre(max_l,x)
% MATLAB HELP:
%
% function [legendreP]=calc_legendre(max_l,x)
%
% recursive calculation of the legendre polynomials up to degree
% max_l , evaluated at x (which can be a vector)
%
% aaron birch may 22 2002 
legendreP=zeros(max_l,length(x));
legendreP(1,:)=x;
legendreP(2,:)=(3*x.*legendreP(1,:)-1)/2;

for (l=3:max_l)
     legendreP(l,:)=( (2*l-1)*x.*legendreP(l-1,:)-(l-1)*legendreP(l-2,:))/l;
end;