function st = spl_val(s,t) 

% SPL_VAL : evaluation of splines
% st = spl_val(s,t) 
% points p(j,:) on a spline s 
% with control points s.c(k,:) and knots s.tau(k) 
% at t(j)

[lc,dim] = size(s.c);
n = length(s.tau) - lc - 1;
c = [zeros(n+1,dim); s.c; zeros(n+1,dim)];
tmax = repmat(2*norm([s.tau; t],inf),n+1,1);
tau = [-tmax; s.tau; tmax];

for j = 1:length(t)
   kj = find(tau(1:end-1) <= t(j) & ... 
       tau(2:end) > t(j));
   stj = c(kj-n:kj,:);
   for m = 1:n 
      ind = [kj-n+m:kj];
      gamma = repmat(((t(j) - tau(ind)) ./ ... 
         (tau(ind+n+1-m) - tau(ind))),1,dim);
      stj = gamma .* stj(2:end,:) + ... 
         (1-gamma) .* stj(1:end-1,:);
   end 
   st(j,:) = stj;
end