function [xp,w] = FEM3x3Gausspts
  
  ix = Q27index;
  a = sqrt(3/5);     % three point rule
  
  xp = a*ix;        % array of Gauss point coordinates in master element.
  ax = [5/9,8/9,5/9]'; 
  go = ix+2;         % turned into an index matrix acting on ax.
  w = ax(go(:,1)).*ax(go(:,2)).*ax(go(:,3));   % weights attached to gausspt.