function [rt,d] = rspl_val(r,t) 

% RSPL_VAL : evaluation of rational splines
% [rt,d] = rspl_val(r,t) 
% points rt(j,:) and weight points $d(k,:)$ 
% for a rational spline r 
% with control points r.c(k,:), weights r.w(k), 
% and knots r.tau(k) at t(j)

d = size(r.c,2);
wd = repmat(r.w,1,d);
s.c = [wd.*r.c r.w];
s.tau = r.tau;
rt = spl_val(s,t);
rt = rt(:,1:end-1)./repmat(rt(:,end),1,d);

d = (wd(1:end-1,:).*r.c(1:end-1,:) + ... 
     wd(2:end,:).*r.c(2:end,:)) ./ ...
    (wd(1:end-1,:) + wd(2:end,:));