from jhplot  import * 

p=P1D("Data")
p.add(1, 9, 3); p.add(2, 21, 5); p.add(3, 36, 6)
f=F1D('10+x*x*x',1,3)
print p.compareChi2(f)
c=HPlot()
c.visible()
c.setAutoRange()
c.draw(p);  c.draw(f)