1 | initial version |
I would say that the plotting is messed with points of very high ordinate. To fix this, you can first give a name to your plot:
sage: p = plot(csc(x), (x,-3*pi, 3 * pi))
And then render it by limiting the ordinate, say, to the interval $[-4,4]$:
sage: p.show(ymin=-4, ymax=4)