function [pospg,wpg] = Quadrature(ngaus) 
% [pospg,wpg] = Quadrature(ngaus) 
%
% pospg, wpg:  Gauss points and weights on the reference element
% ngaus:       number of Gauss points in the element
%
 
if (ngaus == 4) 
   pos1 = 1/sqrt(3); 
   pospg = [-pos1 -pos1 
             pos1 -pos1 
             pos1  pos1 
            -pos1  pos1]; 
   wpg = [ 1 1 1 1]; 
else 
   error(' Unavailable quadrature') 
end 
 
           
