Why do I receive NaNs when using the GRIDDATA function from MATLAB 6.5 (R13)?

Why do I receive NaNs when using the GRIDDATA function from MATLAB 6.5 (R13)?

Using the following code in Unix and Mac:

x=sort(repmat(0:9,1,9))';

y=repmat(0:9,1,9)';

z=x.^2+y.^2;

gridres=35;

xi=[min(x): (max(x)-min(x))/gridres :max(x)];

yi=[min(y): (max(y)-min(y))/gridres :max(y)]';

[x2,y2,z2]=griddata(x,y,z,xi,yi);

surf(x2,y2,z2);

returns NaNs in the surface plot, resulting in holes in my plot. Using the same code on a Windows platform gives me no NaNs (holes) in the surface plot. The default "linear" interpolation of GRIDDATA is used.

Answer 1

[MathWorks Support Team]

This is a bug in MATLAB 6.5 (R13). Our development staff is investigating this issue.

To work around this issue, please try to use the MATLAB 4 GRIDDATA format. In this format, the GRIDDATA command is changed to the following:

[x2,y2,z2]=griddata(x,y,z,xi,yi,'v4');