[R] arrow head styles?

[ivo_welch-rstat8303@mailblocks.com]

dear R wizards:  is it possible to specify different arrow head styles? 
  E.g., a solid arrow head?  Or a bent arrow head?  Or a longer or 
shorter arrow head?  (perhaps through an add in?)  I guess I could 
write this myself, but since arrows is built-in, I was hoping it had 
some flexibility hidden in it that I did not see in "?arrows".

sincerely,  /iaw

---
ivo welch