function e = edge_gort ( )

%*****************************************************************************80
%
%% edge_gort(): the IJ nodes bounding the Gort polyiamond.
%
%  Discussion:
%
%    5           x x x x-x x             16     12 - 11
%                 /\  / /                / \    /     /
%    4         x-x x x x x         18 -17  15 13    10
%             /    \/ /            /        \ /    /
%    3       x-x x x x x         19 -20     14    9
%              \    /                  \         /
%    2     x x x x x x                 21       8
%             /     \                  /          \
%    1   x-x-x x x x         24 -23 -22             7
%       /         /          /                    /
%    0 x-x-x-x-x-x          1 - 2 - 3 - 4 - 5 - 6
%    J                     (25)
%
%    I 0 1 2 3 4 5          Location of edge nodes
%
%    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:
%
%    05 November 2020
%
%  Author:
%
%    John Burkardt
%
%  Output:
%
%    integer E(EN,2): the (I,J) parallelogram point coordinates
%    of the consecutive nodes that form the edges that bound the polyiamond.
%
  e = [ ...
    0, 0; ...
    1, 0; ...
    2, 0; ...
    3, 0; ...
    4, 0; ...
    5, 0; ...
    5, 1; ...
    4, 2; ...
    4, 3; ...
    4, 4; ...
    4, 5; ...
    3, 5; ...
    3, 4; ...
    3, 3; ...
    2, 4; ...
    1, 5; ...
    1, 4; ...
    0, 4; ...
    0, 3; ...
    1, 3; ...
    2, 2; ...
    2, 1; ...
    1, 1; ...
    0, 1 ];

  return
end

