+ curve(pos = ps, color=color)
+ def circle(vd, c, axis, **kw):
+ ring(pos=c, axis=axis, radius=np.linalg.norm(axis), thickness=0.005, **kw)
+ def arrow(vd, p, d, **kw):
+ print('arrow %s' % repr(kw), file=sys.stderr)
+ bodge_color = kw.get('color', (1,0,0))
+ try: del kw['color']
+ except KeyError: pass
+ vd.line(p, p+d, color=bodge_color, **kw)
+ vd.circle(p, np.asarray(d) * 0.25, color=bodge_color, **kw)