function [H2,x2,y2]=xyrecur_max(He,xe,ye,niter)
%
% Returns the gridded data on a grid of half the size
% with the maximum (highest) data moved to the cell-centers.
%
% e.g.
%      [H2,x2,y2]=xyrecur_max(He,xe,ye);

H2=He;
x2=xe;
y2=ye;

% Recursively iterate
for nit=1:niter,
disp(sprintf(' Recursion level %i (%i,%i) -> (%i,%i) ... ',nit,nx,ny,nx/2,ny/2));

[nx,ny]=size(H2);

ii=1:2:nx-1;
jj=1:2:ny-1;

H2=max( max(H2(ii,jj),H2(ii+1,jj)) , max(H2(ii,jj+1),H2(ii+1,jj+1)) );
x2=(x2(ii)+x2(ii+1))/2;
y2=(y2(jj)+y2(jj+1))/2;

disp('done.');

end