function edge_print ( e, label )

%*****************************************************************************80
%
%% edge_print() prints the edges bounding a polyiamond.
%
%  Discussion:
%
%    The edge list contains the sequence of parallelogram IJ coordinates
%    of the nodes that lie on the boundary of the polyiamond, listed
%    in counterclockwise order.
%
%  Licensing:
%
%    This code is distributed under the MIT license.
%
%  Modified:
%
%    09 November 2020
%
%  Author:
%
%    John Burkardt
%
%  Input:
%
%    integer E(EN,2), the IJ parallelogram point coordinates of the 
%    vertices forming the edges around the polyiamond.  
%
%    string LABEL, a label to be printed.  
%
  fprintf ( 1, '\n' );
  fprintf ( 1, '%s\n', label );
  fprintf ( 1, '\n' );

  [ en, n ] = size ( e );

  if ( n ~= 2 )
    fprintf ( 1, '\n' );
    fprintf ( 1, 'polyiamond_print_edge - Fatal error!\n' );
    fprintf ( 1, '  Input array E has column dimension %d, should be 2.\n', n );
    error ( 'polyiamond_print_edge - Fatal error!' );
  end

  if ( en <= 0 )
    fprintf ( 1, '  [ Null array ]\n' );
  else
    for i = 1 : en
      fprintf ( 1, '  %2d:', i );
      for j = 1 : 2
        fprintf ( 1, ' %d', e(i,j) );
      end
      fprintf ( 1, '\n' );
    end
  end

  return
end

