load www.dat
g=www
x=g(:,1)
y=g(:,2)
z=g(:,3)
[xx,yy]=meshgrid(x,y);
zz=griddata(x,y,z,xx,yy,'v4');
index = find(xx.^2+yy.^2 > 0.162^2);
zz(index) = NaN;
mesh(xx,yy,zz)