Hans et al,
I think I've found something that works. I know ahead of time that
there will only be two crossings of the clipping path boundary (I make
sure of the by the parameters I choose):
beginfig(0);
% initialize a, h, and h for f(x)=ax^2+bx+c=a(x-h)^2+k
numeric a, h, k;
a=-1;
h=-3;

Hans et al,
I tried what follows. But as far as I can see, I am not getting back a
path q that is clipped to the cpath.
vardef lastpath (expr p) =
save _p_ ; path _p_ ; _p_ := origin ;
for i within p :
if stroked i : _p_ := pathpart i ; fi ;
endfor ;

David Arnold wrote:
Hans et al,
Let me try to be more specific. Here is a file which is very typical
of the way I draw graphs for my mathematics classes. When you compile,
you will see the graph of the absolute value of x-1. That is, it draws
the graph of y=|x-1|, but only after clipping it

Hans et al,
Let me try to be more specific. Here is a file which is very typical of
the way I draw graphs for my mathematics classes. When you compile, you
will see the graph of the absolute value of x-1. That is, it draws the
graph of y=|x-1|, but only after clipping it to the cpath. What I