How to calculate derivation of 2D spline data

I know there's method to calculate derivation of 1d spline data, but how to calculate 2d spline data?

asuming there's 2d data : ZZ(XX,YY)

How to calculate the derivation of data (XX,YY,ZZ)?

Answer 1

[KSSV]

REad about gradient

[Yueyan Li]

not the gradient on the grid, but at arbitrary position, so gradient is not what I need.

Also I don't want to break the continuity of the spline, so I don't want to do a spline for the gradient.

[KSSV]

syms x y z
z = cos(x).*exp(-y^2);
dz = diff(z,x)

[Yueyan Li]

that's just an example, I already delete the example to avoid your confusion.