Re: Reverse function numerically

[Juan Pablo Carbajal]

The modeling function is what you want to find.

If f(x1,x2) is continuously differentiable (as your example) then
split the domain where det(J f) == 0 and obtain local inverses using
root finding (this exploits the existence of the inverse function
based on the implicit function theorem).

For each domain, make a unstructured triangular mesh and use 2D
polynomial interpolation. However since your inverse looks like a
rational function, maybe splines are a better option.