# 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?

Some information seems missing. Evaluating p1 does not work for me. How are p and q related to x,y,z ?

@tmonteil Sorry for misleading notation. X, y and z are functions in two variables p and q.