Interpolation - Polynomial - 3D Graph

1- Hello everybody,

1- How do I perform a cubic interpolation of a function with 3 variables? I have Zf(ρ,α,X0)

2- 2- After interpolation, How do I generate the actual cubic polynomial with my 3 variables?

3- 3- How do I make a 3D graph showing my results?

I have attached my calculation in a MathCad file (ver.14). Please go to the end of the worksheet to see my work on the problems mentioned above.

I had to do the interpolation manually. i.e. creating vectors for ρ, α and X0. You can see that I could generate polynomial coefficients (20 of them!) but, don’t know how to create the actual polynomial.

The polynomial written in the worksheet (highlighted) is done by generating the coefficients in EXCEL.

Important task would be to do the interpolation by using my original function and variables.

Thank you so much for your time and help.

Anousheh