#

# Estimate pi
?par

# Save old parameter values
old.par <- par()
par(pty="s")                                # Sets the plot region to be square

# Generate random numbers
?runif

num.pts <- 5000
x <- runif( num.pts, min=-1, max=1 )
hist(x)
y <- runif( num.pts, min=-1, max=1 )
plot(x,y)
plot(x,y, xlim=c(-1.5, 1.5), ylim=c(-1.5, 1.5) )

# Plot the circle
t <- seq(0, 2*pi, length=100)
lines( cos(t), sin(t), lwd=2, col=4 )

# Plot lines
abline(v=1, col=2)
abline(v=-1, col=3)
abline(h=-1, col=4)
abline(h=1, col=5)
mod <- sqrt(x^2 + y^2)
ratio <- sum(mod<1)/length(mod)
ratio * 4

par(old.par)                                # Reset deafult pars

# Print the picture as postscript
dev.print(postscript, file="testfile.eps")