#*****************************************************************************80
#
## price_plots reads price data and plots 3 prices on one display.
#
#  Licensing:
#
#    This code is distributed under the MIT license.
#
#  Modified:
#
#    25 August 2020
#
#  Author:
#
#    John Burkardt
#
cat ( "\n" )
cat ( "price_plots:\n" )
cat ( " ", version$version.string, "\n" )
cat ( "  Plot prices of bananas, gas and milk over time.\n" )
#
#  Read the data.
#
filename = "price_data.txt"
data <- read.table ( filename, header = FALSE )
n = dim(data)[1]
x = seq ( 1, n )
#
#  Plot three curves on one image.
#
filename = "price_plots.png"
png ( filename )

plot ( x, data[,3],
  xlab = "<--- Month index --->",
  ylab = "<--- Price in Dollars --->",
  main = "Prices, Feb 2008-Feb 2018",
  col = "red",
  type = 'l',
  lwd = 3,
  ylim = c ( 0.0, 5.0 ) )

lines ( x, data[,10], type = 'l', col = "blue", lwd = 3 )

lines ( x, data[,13], type = 'l', col = "green", lwd = 3 )

x = 25.0
y = 4.0
legend ( x, y, legend = c ( "red: Bananas",  "blue: Gas", "green: Milk" ) )

grid ( )

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