I assume you want to plot that data.
Well the most obvious way would be to just plot the lines with
plot3(Xout, Yout, Zout);
But that might not satisfy your needs...
So lets do something different
% 1. Create a grid
% 1.1 for that create grid vectors of your choice
x = [0:100];
y = [0:10:1000];
% 1.2 Create a 2D Grid of these vectors (please not that X ist not equal to x)
[X,Y] = meshgrid(x,y);
% 2. Interpolate
% 2.1 no need to use fit, simply do that with
Z = griddata(Xout,Yout,Zout,X,Y);
% 3. Plot
hdl = surf(X,Y,Z);
% 4. Make the figure nicer, f.ex
ax = gca;
ax.CLim = [3.2, 3.7]; % adjusts the colorbar to your needs
hdl.EdgeAlpha = 0.5; % makes lines slightly transparent
This gives you something like this:
