#! /usr/bin/env python3
#
def moler_incidence ( ):

#*****************************************************************************80
#
## moler_incidence() returns the incidence matrix for example 3.
#
#  Discussion:
#
#    This matrix appears on page 5 of the reference.
#
#    We added a self-link for node 5, which otherwise has no outlinks.
#
#  Licensing:
#
#    This code is distributed under the GNU LGPL license.
#
#  Modified:
#
#    10 April 2022
#
#  Author:
#
#    John Burkardt
#
#  Reference:
#
#    Cleve Moler,
#    Experiments with Matlab,
#    Chapter 7: Google PageRank,
#    https://www.mathworks.com/moler/exm/chapters/pagerank.pdf
#
#  Output:
#
#    integer A(6,6), the incidence matrix.
#
  import numpy as np

  A = np.zeros ( [ 6, 6 ] )

  A = np.array ( [ \
    [ 0, 1, 0, 0, 0, 1 ], \
    [ 0, 0, 1, 1, 0, 0 ], \
    [ 0, 0, 0, 1, 1, 1 ], \
    [ 1, 0, 0, 0, 0, 0 ], \
    [ 0, 0, 0, 0, 1, 0 ], \
    [ 1, 0, 0, 0, 0, 0 ] ] )

  return A

if ( __name__ == '__main__' ):
  A = moler_incidence ( )
  print ( A )