2D Contour Plot and Zero of a 1D function

I couldn't find a method in Grasshopper to find the zero of a 1D function. So I created on and I'm sharing it.

I also didn't find anything about contour plots. So I made one (probably there is a faster and better way.

A Better Way using points to surface.

On of the problems with this methods are discontinuities of the contour, inflection points. And Very hight values out of plane gives poor result.

I had made a projection operator, that project a point to a equation in the form f(x,y,z) = 0. But a better way would be create a Refine function. But the draw back would be the impossibility of creating a surface from a grid, like I did. Beucase Refine would add more points.

I'm open to suggestions (or if already has a post on this, the source of it)

Thanks

EDIT: That second flatten is useless. Fogot it.