Interpolate value of point

Hello. I have a sufrace like on the image.How can I interpolate z-value (black cross) from this surface? I need the fastest methos (linear, for example)

Answer 1

[Bob Thompson]

I'm assuming you have the data for the surface points. If so, I believe interp2 will do what you're asking.

[Aleksey Gureev]

Hello. Thank you for your answer. How can I use it? I tried like this

interp2(X, Y, V, 0, 0) - if I want to get at x = 0, y = 0, but It doen't work for me. Numbers in X and Y not monotonic.

[Aleksey Gureev]

Solved

xv = linspace(min(x), max(x), 20);

yv = linspace(min(y), max(y), 20);

[X,Y] = meshgrid(xv, yv);

Z = griddata(x,y,z,X,Y);

interp2(X, Y, V, 0, 0)