function [xmin, xmax, ymin, ymax]  = bare_mesh_overlay (inc_e, inc_p) 
% Copyright 2007, J.E. Akin.  All rights reserved.
%  ------------------------------------------------------
%             bare minimum borders
%  Matlab program to calculate & plot 2-D FE meshes
%  ------------------------------------------------------

% c_x    = x coordinates of nod_per_el line polygon
% c_y    = y coordinates of nod_per_el line polygon
% inc_e  = increment in element numbers on plot, if > 0
% inc_p  = increment in node numbers on plot, if > 0
% msh_typ_nodes   = connectivity list for elements, nt x nod_per_el
% loop   = corners for nod_per_el line polygon
% lab_p  = 1, if node points are circled
  lab_p  = 0;
% nod_per_el = Nodes per element
% np     = Number of Points
% nt     = Number of elements
% pre_e  = Element items before type & connectivity list
% pre_p  = Nodal items before coordinates
% msh_bc_xyz = Nodal coordinates (with preceeding data)
% t_x    = x coordinates of nod_per_el corners
% t_y    = y coordinates of nod_per_el corners
% xy     = Coordinates of points, np x 2

pre_e  = 0  ;
pre_p = 1;

%    Read coordinate file and connectivity file
%    integer bc code, real xy pairs for np points (pre_p = 1)

%    Set control data: number of points
  load msh_bc_xyz.tmp ;  
  np = size (msh_bc_xyz,1) ;   % number of nodal points  
  ns = size (msh_bc_xyz,2) - pre_p ;   % dimension of space
  if ( np == 0 )
    error ('Error missing file msh_bc_xyz.tmp')
  end % if error

  x (np)      = 0.       ;       % pre-allocate array x
  y (np)      = 0.       ;       % pre-allocate array y

  % msh_bc_xyz has: pre_p items then: x, y
  x = msh_bc_xyz (1:(np), (pre_p+1)) ; % extract x  %CL
  if ( ns >= 2)
    y = msh_bc_xyz (1:(np), (pre_p+2)) ; % extract y %CL
  else
    y (1:np) = 0. ;
  end % if 1D
  
%    Set control data: number elements & nodes_per_element
  load  msh_typ_nodes.tmp ; % nod_per_el nodes per element
  nt = size (msh_typ_nodes,1);           % number of elements 
  if ( nt == 0 )
    error ('Error missing file msh_typ_nodes.tmp')
  end % if error
  nod_per_el = size (msh_typ_nodes,2) - pre_e -1 ; % nodes per element
  Col_1 = pre_e+2 ; %CL
  Col_2 = nod_per_el+pre_e+1 ; %CL
  Types = msh_typ_nodes(:,pre_e+1) ;
  n_type = max(Types) ;

  [M_min, J_min] = min ( msh_typ_nodes (1:nt, Col_1:Col_2) ); %CL

  t_nodes (nod_per_el) = 0 ;    % Optional pre-allocation
  t_x (nod_per_el) = 0 ;        % Optional pre-allocation
  t_y (nod_per_el) = 0 ;        % Optional pre-allocation
  c_x (nod_per_el + 1) = 0 ;    % Optional pre-allocation
  c_y (nod_per_el + 1) = 0 ;    % Optional pre-allocation
  loop (nod_per_el + 1) = 0 ;   % Optional pre-allocation
 
%                set constants
  [loop] = get_El_Loop (nod_per_el) ;

%    Initialize plots
  xmax = max (x)      ; xmin = min (x) ;
  ymax = max (y)      ; ymin = min (y) ;
  xdiff = xmax - xmin ; ydiff = ymax - ymin ;
  if ( ydiff == 0.0 )
    ydiff = 0.1 * xdiff ; % allow for 1-D mesh (with y == 0)
    ymax = ymin + ydiff ;
  end % if no y coordinates
  % xmax = xmax + xdiff/10; ymax = ymax + ydiff/10;
  % xmin = xmin - xdiff/10; ymin = ymin - ydiff/10;
  clf                               % clear graphics
  axis ([xmin, xmax, ymin, ymax])   % set axes
  axis ('equal')                    % true shape style
  hold on                           % hold image for plots
  grid                              % add grid dots
  xlabel ('X')                      % add label
  ylabel ('Y')                      % add label

 
   in_mesh (1:np) = 1 ;               % default to missing

%    Loop over all elements
  for it = 1:nt  ;

%      Extract corner connectivity 
    t_nodes = msh_typ_nodes ((it), Col_1:Col_2 ) ; %CL
    [N_min, I_min] = min ( t_nodes ) ;

%      Extract corner coordinates
    t_x  = x (t_nodes) ;         % x at those nodes, only
    t_y  = y (t_nodes) ;         % y at those nodes, only

%      Plot this polygon
    c_x  = t_x (loop) ;       % x for nod_per_el line polygon
    c_y  = t_y (loop) ;       % y for nod_per_el line polygon
    plot (c_x, c_y)           % plot nod_per_el lines
  end % for over all elements
 
%       -depsc -tiff            % for an eps version
  % print -deps2 mesh_overlay
  hold off
% end of bare_mesh_overlay