How to fill outside of contourf plot based on x,y,z data

I have the following script:

B13data= csvread('B13_Sep2015.csv',1,0);

%Create x,y,z values
x=B13data(:,1);
y=B13data(:,2);
z=B13data(:,3);

%Make a range of x and y data points for contour
xi=linspace(min(x),max(x),40);
yi=linspace(min(y),max(y),40);

%Mesh the x and y data
[XI YI]=meshgrid(xi,yi);

%Interpolate original data with the meshed data range
ZI=griddata(x,y,z,XI,YI);

%Contour meshed data
contourf(XI,YI,ZI)
colorbar;

X and Y are the x and y-coordinates and the corresponding z-value is the elevation. When I plot, it cuts off at the points where I didn't collect data. How do I proceed to extend the plot to make it look more full based on the data I already have?

Answer 1

[Walter Roberson]

You might want to try John D'Errico's File Exchange contribution inpaint_nans

[Kelli]

Thanks! I'll check that out!