## Title: plot-histogramWithLinesAndLegend.R
## Author: Paul E Johnson
## Date: 2013-02-11
## Description: Show ways to customize a histogram.
## This one runs into problem that there is not enough
## room in the top of the figure for a legend. We have
## choices to make margins bigger or to allow the
## plotter to draw outside the "plot region" (xpd=TRUE)
## Thanks to r-help members for tips.
x <- rnorm(100)
###Allows writing outside plotting region
par(mai=c(1,1,2.5,1)) ## margins
par(xpd=TRUE) ## write outside plot region
myhist <- hist(x, prob = TRUE, main="Different Meanings of Normality")
lines(density(x))
xseq1 <- seq( min(x), max(x), length.out=100)
m1 <- mean(x)
sd1 <- sd(x)
obsNormal <- dnorm(xseq1, mean=m1, sd=sd1)
lines( xseq1, obsNormal, lty=2, col="red")
truNormal <- dnorm(xseq1)
lines(xseq1, truNormal, lty=3, col="green")
legend(min(xseq1),1.3*max(myhist$density), legend=c("observed density", "normal with observed mean & sd", "normal with 'true' mean and sd"), lty=c(1,2,3), col=c("black", "red", "blue"))