// plot all points as function of position
objref rvp_
proc spaceplot() { // arg is Graph instance
	mcab[0] {distance(0,0)}
	forsec "mcab" { sp1($o1, 2) }
	ecab[0] {distance(0,0)}
	forsec "ecab" { sp1($o1, 1) }
}
proc sp1() {
	rvp_ = new RangeVarPlot("v")
	rvp_.begin(0)
	rvp_.end(1)
	rvp_.origin(distance(0))
	$o1.addobject(rvp_, $2, 1, -1, 0)
}