function [loop] = get_El_Loop (face)
%   ------------------------------------------------------
%  Get node loop to draw an element by closing to first node.
%          Draw any interior nodes at the first node.
%   ------------------------------------------------------
% loop   = corners for face line polygon
% Drawing connection order for 6 faces
% f1 1 2 3 4 & 1
% f2 1 5 6 2 & 1
% f3 2 6 7 3 & 2
% f4 3 7 8 4 & 3

  loop = [ 1:3, 1]; % default for  face 1
  if (face == 2 )    
    loop = [1, 2, 4, 1]; 
  elseif (face == 3 ) 
    loop = [2, 3, 4, 2];
  elseif (face == 4 )  
    loop = [1, 3, 4, 1]; 
  end % if
% end function get_El_Loop for P4