how to change values within an array to NaN

loading xyz-data into Matlab and interpolate that scattered data like this:

load f56.dat
x=f56(:,1);  y=f56(:,2);  z=f56(:,3);
F=scatteredInterpolant(x,y,z);
[xn yn]=meshgrid(min(x):0.01:max(x),min(y):0.01:max(y));
zn=F(xy,yn);

gives me 1950 values in x and 4000 in y.

Because of a region of bad data I would like to set that region to NaN for further processing. How can I set 1280 <= x <= 1950 and 3025 <= y <= 4000 to NaN ?

Thanks a lot.

Answer 1

[Matt J]

zn = F(xn,yn);

bad = (1280 <= xn & xn<=1950)  & (3025 <= yn & yn <= 4000) ;

zn(bad)=nan;

[Harald von der Osten]

oh...much easier than I thought it would be...thanks a lot :-)