forall delete_section()
//@code
create a
access a
Ra=100
nseg = 10
pt3dclear()
for i=0,30 {
	x = PI*i/30
	pt3dadd(200*sin(x), 200*cos(x), 0, 100*sin(4*x))
}
objref s
s = new Shape()
s.show(0)
print L
for (x) print x, diam(x), area(x), PI*diam(x)*L/nseg, ri(x), .01*Ra*(L/2/nseg)/(PI*(diam(x)/2)^2)