#*****************************************************************************80
#
## circle_scatters plots data in and out of a circle.
#
# Licensing:
#
# This code is distributed under the GNU LGPL license.
#
# Modified:
#
# 02 September 2020
#
# Author:
#
# John Burkardt
#
cat ( date ( ), "\n" )
cat ( "\n" )
cat ( "circle_scatters\n" )
cat ( " ", version$version.string, "\n" )
cat ( " Make scatter plots of two sets of data representing" )
cat ( " points inside, and points outside the unit circle." )
#
# Read the data.
#
filename = "circle1_data.txt"
data1 <- read.table ( filename, header = FALSE )
filename = "circle2_data.txt"
data2 <- read.table ( filename, header = FALSE )
#
# Generate points on a circle.
#
n = 50
circle = matrix ( nrow = n, ncol = 2 )
for ( i in 1 : n )
{
theta = 2 * pi * ( i - 1 ) / ( n - 1 )
circle[i,1] <- cos ( theta );
circle[i,2] <- sin ( theta );
}
#
# Plot the data
#
filename = "circle_scatters.png"
png ( filename )
plot ( circle[,1], circle[,2],
lwd = 3,
type = "l",
col = "black",
xlab = "<--- X --->",
ylab = "<--- Y --->",
main = "Random points inside/outside the unit circle" )
points ( data1[,1], data1[,2], col = "blue" )
points ( data2[,1], data2[,2], col = "red" )
grid ( )
cat ( ' Graphics saved as "', filename, '"\n' )
#
# Terminate.
#
cat ( "\n" )
cat ( "circle_scatters:\n" )
cat ( " Normal end of execution.\n" )
quit ( )