tsp_dantzig42_xy <- function ( )

#*****************************************************************************80
#
## tsp_dantzig42_xy() returns the location data for the Dantzig 42 city TSP challenge.
#
#  Discussion:
#
#    The original values 
#
#     147.5,  36.0; ...
#     154.5,  45.0; ...
#
#    were adjusted to 
#
#     147.0,  36.0; ...
#     154.0,  45.0; ...
#
#    so that all coordinates are integers.
#
#  Licensing:
#
#    This code is distributed under the MIT license.
#
#  Modified:
#
#    26 July 2026
#
#  Author:
#
#    John Burkardt
#
#  Output:
#
#    real tsp_dantzig42_xy(42,2): the x and y coordinates of the cities.
#
{
  dantzig42_xy = matrix ( c (
      170.0,  85.0,
      166.0,  88.0,
      133.0,  73.0,
      140.0,  70.0,
      142.0,  55.0,
      126.0,  53.0,
      125.0,  60.0,
      119.0,  68.0,
      117.0,  74.0,
       99.0,  83.0,
       73.0,  79.0,
       72.0,  91.0,
       37.0,  94.0,
        6.0, 106.0,
        3.0,  97.0,
       21.0,  82.0,
       33.0,  67.0,
        4.0,  66.0,
        3.0,  42.0,
       27.0,  33.0,
       52.0,  41.0,
       57.0,  59.0,
       58.0,  66.0,
       88.0,  65.0,
       99.0,  67.0,
       95.0,  55.0,
       89.0,  55.0,
       83.0,  38.0,
       85.0,  25.0,
      104.0,  35.0,
      112.0,  37.0,
      112.0,  24.0,
      113.0,  13.0,
      125.0,  30.0,
      135.0,  32.0,
      147.0,  18.0,
      147.0,  36.0,
      154.0,  45.0,
      157.0,  54.0,
      158.0,  61.0,
      172.0,  82.0,
      174.0,  87.0 ), nrow = 42, ncol = 2, byrow = TRUE )

  return ( dantzig42_xy )
}