function [pn]=norma_post(p)
%
% [pn]=norma_post(p)
% pn has one 4-element row for each point

[sprow spcol]=size(p);

for m=1:sprow
   if p(m,4)~=0 
       pn(m,:)=p(m,:)/p(m,4); 
   end
end