Rescaling -- want curve, and arrows to look nice on same screen

Calculate the maximal value of the magnitude of the curvature:

>    cmax  :=max(op(map(abs,ccurv)));

cmax := 10.45800967

Define the absolute size of the longest arrows in terms of screen size

>    relsize:=0.2;

relsize := .2

>    sTT:=map(q->relsize*rsize*q,TT):
sNN:=map(q->relsize*rsize*q,NN):
if cmax > 0 then
   ccurv:=map(q->q/cmax,ccurv);
   end:
cN:=zip((k,N)->[k*N[1],k*N[2]],ccurv,sNN):

>    TNstatic:=display([curve,
         op(zip((x,y)->arrow(x,2/3*y,color=cyan,thickness=4),rr,sTT)),
         op(zip((x,y)->arrow(x,2/3*y,color=magenta, thickness=4),rr,sNN))]):