second order interpolation
 

Hello guys
I have 2D function and want to do second order interpolation, any body knows the formula? :confused:
Thanks.
White heart

Try to use a second order 2D polynomial, fit this to your data points and then use least squares to obtain the coefficients, this will work on kind of grids.

Or search in a numerical methods book for 2D interpolations (if I remember well there is a Lagrange formula for regular grids).

Do