[metapost] Plotting step functions

[Troy Henderson]

How about something like this:

vardef stepfunc primary p =
	save q;
	path q;
	q:=(point 0 of p) for n=1 upto length p: --(xpart point (n-1) of p,ypart point n of p)--(point n of p) endfor;
	q
enddef;

and then use it in the following way:

path p;
p:=(0,0)--(10,10)--(15,5)--(20,10);
draw p;
draw stepfunc p withcolor blue;

Troy