The following code (straight from http://doc.sagemath.org/html/en/reference/plot3d/sage/plot/plot3d/shapes2.html) does not work in the SageMath Cloud, at least not for me:
from sage.plot.plot3d.shapes2 import Line
Line([(i*math.sin(i), i*math.cos(i), i/3) for i in range(30)], arrow_head=True)
The result is a long error message ending with "TypeError: 0 is not JSON serializable". Am I doing something wrong?
