#*****************************************************************************80
#
## iris_subplots creates a scatter plot from Corvette data.
#
#  Licensing:
#
#    This code is distributed under the MIT license. 
#
#  Modified:
#
#    07 September 2020
#
#  Author:
#
#    John Burkardt
#
cat ( date ( ), "\n" )
cat ( "\n" )
cat ( "iris_subplots\n" )
cat ( " ", version$version.string, "\n" )
cat ( "  For each of 3 varieties of iris, a number of specimens\n" )
cat ( "  have been collected.  For each specimen, measurements\n" )
cat ( "  made of sepal length (x1), sepal width (x2), petal length (x3)\n" )
cat ( "  and petal width (x4).\n" )
cat ( "\n" )
cat ( "  Create a 4x4 array of scatter plots that compare each\n" )
cat ( "  pair of values.  Moreoever, use colors to distinguish the\n" )
cat ( "  data belonging to each of the three varieties.\n" )
#
#  Read the three sets of x1, x2, x3, x4 data:
#
filename = "iris_setosa_data.txt"
setosa <- read.table ( filename, header = FALSE )
filename = "iris_versicolor_data.txt"
versicolor <- read.table ( filename, header = FALSE )
filename = "iris_virginica_data.txt"
virginica <- read.table ( filename, header = FALSE )
#
#  Request a 4 x 4 array of plots.
#
par ( mfrow = c ( 4, 4 ) )
#
#  Request bottom, left, top, right margin sizes.
#
par ( mar = c ( 0.1, 0.1, 0.1, 0.1 ) )
#
#  Create the plots.
#
filename = "iris_subplots.png"
png ( filename )

for ( i in 1 : 4 )
{
  for ( j in 1 : 4 )
  {
    plot (
      setosa[,i], setosa[,j], col = "red",
      lwd = 3,
      type = "p",
      xaxt = "n",
      yaxt = "n",
      ann = FALSE )
    points ( versicolor[,i], versicolor[,j], col = "green" )
    points ( virginica[,i], virginica[,j], col = "blue" )
    grid ( )
  }
}
cat ( '  Graphics saved as "', filename, '"\n' )
#
#  Terminate.
#
cat ( "\n" )
cat ( "iris_subplots:\n" )
cat ( "  Normal end of execution.\n" )

quit ( )