
 Frenet Frame Display Package (Site not responding. Last check: 20071024) 
  # Typical usage: T([f(var),g(var),h(var)],var); T := proc(gamma,t) local T_len,T_before; T_before := vector(3,tang(gamma,t)); T_len := sqrt(norm(T_before,2)); evalm((1/T_len) * T_before) end: subs2 := proc(a,b) subs(b,a) end: # Return a Frenet frame and curvature at a parameter value t=t0. 
  Pi,2); # Return a graph of num_steps Frenet frames, equally spaced along the curve gamma. 
  # Each frame is drawn with T in red, N in blue, and B in green. 
 mathlab.cit.cornell.edu /local_maple/mvc/Math222/lib/frame6 (178 words) 
