#*****************************************************************************80
#
## genealogy_tree plots a binary tree for alphabetizing.
#
#  Licensing:
#
#    This code is distributed under the MIT license. 
#
#  Modified:
#
#    04 September 2020
#
#  Author:
#
#    John Burkardt
#
cat ( date ( ), "\n" )
cat ( "\n" )
cat ( "genealogy_tree\n" )
cat ( " ", version$version.string, "\n" )
cat ( "  Plot a tree illustrating a genealogy." )

library ( igraph )

filename = "genealogy_tree.png"
png ( filename )

G <- graph.tree ( n = 1, children = 2 )
V(G)$name <- "George"
V(G)$color <- "cyan"

G <- G + vertices ( "Martha", color = "pink" )
G <- G + edge ( "George", "Martha" )
G <- G + vertices ( "Cecilie", color = "pink" )
G <- G + edge ( "George", "Cecilie" )

G <- G + vertices ( "Samantha", color = "pink" )
G <- G + edge ( "Martha", "Samantha" )
G <- G + vertices ( "Allen", color = "cyan" )
G <- G + edge ( "Martha", "Allen" )

G <- G + vertices ( "Naomi", color = "pink" )
G <- G + edge ( "Cecilie", "Naomi" )
G <- G + vertices ( "Aram", color = "cyan" )
G <- G + edge ( "Cecilie", "Aram" )

G <- G + vertices ( "Karen", color = "pink" )
G <- G + edge ( "Samantha", "Karen" )
G <- G + vertices ( "Dennis", color = "cyan" )
G <- G + edge ( "Samantha", "Dennis" )
G <- G + vertices ( "Mohit", color = "cyan" )
G <- G + edge ( "Samantha", "Mohit" )

G <- G + vertices ( "Otto", color = "cyan" )
G <- G + edge ( "Naomi", "Otto" )
G <- G + vertices ( "Francine", color = "pink" )
G <- G + edge ( "Naomi", "Francine" )

my_layout <- layout.reingold.tilford ( G, params = list ( root = "George" ) )

plot ( G, layout = my_layout, 
  vertex.size = 30, 
  main = "My genealogy tree" )

cat ( '  Graphics saved as "', filename, '"\n' )
#
#  Terminate.
#
cat ( "\n" )
cat ( "genealogy_tree:\n" )
cat ( "  Normal end of execution.\n" )

quit ( )