plotting a plane section in sage
Suppose I have a parametric surface given by three functions in two variables. Moreover, this surface is immersed in a solid torus like
sage: p1 = parametric_plot(( a*(R + x)*cos(z), a*(R + y)*sin(z), a*y ),(p,0,2*pi),(q,0,2*pi))
for some a and R.
How can one plot a section of the surface by a plane with Sage?