# This script plots six QQ-normal plots for samples of a standard normal.
# Each plot should show small deviations from normality.
n.observations <- 30
# Set up the graphics device.
par(mfrow = c(2, 3))
par(mar = rep(3, 4))
# This allows us to exactly specify the plot window. Otherwise, R will
# slightly expand the plot.
par(xaxs = "i")
par(yaxs = "i")
# Prepare some graphical parameters.
standard.axis <- seq(from = -3, to = 3, by = 1)
axis.size <- 1.5
for(i in 1:6){
qqnorm(rnorm(n.observations), xlim = c(-3, 3), ylim = c(-3, 3),
main = "", xlab = "", ylab = "", xaxt = "n", yaxt = "n", bty = "n")
axis(1, at = standard.axis, cex.axis = axis.size)
axis(2, at = standard.axis, cex.axis = axis.size)
}
# Close the graphics device.
dev.print(device = postscript, "3.12.eps",
horizontal = TRUE, width = 11, height = 7, paper = "special")