function N=neigh(r)
% neigh	Create an neighborhood descriptor for a neighborhood with
%	radius r: 
%		N=neigh(r)
%	The description will not be symmetric.
%
%	Se also: symmetric_ext, unpack_param

N=[0;0];
for i=-r:r,
  for j=-r:0,
    if ~((i>0 & j==0) | (i==0 & j==0) | ((sqrt(i*i+j*j)>r))),
      N=[N [i;j]];
    end
  end
end
N=N(:,2:size(N,2));