Can I obtain the mathematical expression of a Radial basis function interpolation?

Hello everyone. I have recently found this code for Radial Basis Function interpolation.

I have tested it with my own data and it works perfectly. However, I was wondering if there was a way for me to access to the mathematical expression behind the model so that I can calculate the value of the interpolated field anywhere instead of just in the predefined grid points?

Best regards.

Jaime.