[pstricks] Normal arrows along a curve

[James]

Hi,

I am new to PS Tricks, I am trying to draw a (pretty) Neumann boundary 
condition for a problem. What I need is the ability to place outward 
normal vectors along a path. So given a curve, you could draw it with a 
solid line or a dotted line - what I would like is to draw the line 
solid, but in the places where it would have been dotted, to have an 
small outward line with arrow. (or just a slightly smaller point size line)

How difficult is this? I bring up the similarity to a dotted line, 
because if it could be implemented at the "line" level, then you could 
easily draw lines with outward normal arrows using bezier curves, or 
really anything.

Thanks for any help,

James