function [loop] = get_El_Loop (nod_per_el)
%   ------------------------------------------------------
%  Get node loop to draw an element by closing to first node.
%          Draw any interior nodes at the first node.
%   ------------------------------------------------------
% loop   = corners for nod_per_el line polygon
% Drawing connection order for 
% L2  1,2,(1)
% T3  1,2,3,(1)
% Q4  1,2,3,4,(1)
% T6  1,4,2,5,3,6,(1)
% Q8  1,5,2,6,3,7,4,8,(1)
% Q9  1,5,2,6,3,7,4,8,(1),9
% T10 1,4,7,2,5,8,3,6,9,(1),10
% Q12 1,5,9,2,6,10,3,7,11,4,8,12,(1)
% T15 1,4,7,10,2,5,8,11,3,6,9,12,(1),13,14,15
% Q16 1,5,9,2,6,10,3,7,11,4,8,12,(1),13,14,15,16
% Q17 1,5,9,13,2,6,10,14,3,7,11,15,4,8,12,16,(1),17
% Q25 1,5,9,13,2,6,10,14,3,7,11,15,4,8,12,16,(1),
%     17,18,19,20,21,22,23,24,25

  loop = [ 1:nod_per_el, 1]; % default for L2, T3, Q4
  if (nod_per_el == 6 )      % T6
    loop = [1, 4, 2, 5, 3, 6, 1]; 
  elseif (nod_per_el == 8 )  % Q8
    loop = [1, 5, 2, 6, 3, 7, 4, 8, 1]; 
  elseif (nod_per_el == 9 )  % Q9
    loop = [1, 5, 2, 6, 3, 7, 4, 8, 1, 1]; 
  elseif (nod_per_el == 10)      % T10
    loop = [1,4,7,2,5,8,3,6,9,1,1];
  elseif (nod_per_el == 12)      % Q12
    loop = [1,5,9,2,6,10,3,7,11,4,8,12,1] ;
  elseif (nod_per_el == 15)      % T15
    loop = [1,4,7,10,2,5,8,11,3,6,9,12,1,1,1,1];
  elseif (nod_per_el == 16)      % Q16
    loop = [1,5,9,2,6,10,3,7,11,4,8,12,1,1,1,1,1];
  elseif (nod_per_el == 17)      % Q17
    loop = [1,5,9,13,2,6,10,14,3,7,11,15,4,8,12,16,1,1];
  elseif (nod_per_el == 25)      % Q25
    loop = [1,5,9,13,2,6,10,14,3,7,11,15,4,8,12,16,1,1,1,1,1,1,1,1,1,1];
  end % if
% end function get_El_Loop