I have a 'forward' equation that I'm inverting numerically, using a two dimensinol non-linear solver using first derivatives.

Unfortunately as I refine my input mesh, I'm finding more and more input combinations where the reversibility is not accurate enough (the solver isn't reaching the correct solution).

(I have A = f(X, Y) and X' = f(A, Y), so I can check reversibility by examining X-X').

I wonder if it is possible to graphically represent my reversibility results using colours to represent certain tolerances. I was thinking of a picture box(?) with X and Y dimensions equivalent to my input ranges. But I'd also want to be able to identify the inputs from the graphical output, e.g. click on a point and have it report result and inputs...

Any thoughts...?