R is a free statistics software which can be downloaded from
www.r-project.org. After accessing the webpage, you can follow the setup
instructions.  Below are some basic things when you begin to use it.
(Also note that R has been installed in some student computer labs already.
To see which labs have it installed, check website at:
http://www.doit.wisc.edu/computerlabs/software.asp )

First, you need to read the data.  Take Exercise 83 in Chapter 4 as an Example.

1. Download the data set from the TA's course webpage:
www.stat.wisc.edu/~cfan/st324-spring04.html,
you need Data Sets for textbook problems in text files.

2. Set the path for work space to the file where you saved the data.  If
you use R in LINUX, go to the certain directory then open R; if you use R
in Windows, click the menu File -> Change dir ...

3. Read the data to the workspace:

> ex04.83 <- read.table("ex04-83.txt", skip = 1)

4. Rename the data column:

> names(ex04.83) <- c("thickness")

Alternatively, for file (e.g., named "rainfall.dat") consisting of data on
a single variable x (i.e., one sample), as Exer 87 of Chap 4, you can use:

> rainfall <- scan("rainfall.dat")

Or, for small data set on a single variable x, you could enter directly as:

> polymer <- c(418,421,421,422,425,427,431,434,437,439,442,445)

After reading the data into the workspace, you can use it.

1. Plot a normal probability plot: from the help, we know 04.83 has a
column of data named "thickness", so the command below generates the normal
probability plot.

> qqnorm(ex04.83$thickness)

2. Plot the histogram

> hist(ex04.83$thickness)

If alternative way of entering data into R is used, corresponding commands
are just:  qqnorm(rainfall)  and  hist(rainfall)

More commands are availbale from Professor Reinsel's course webpage:
http://www.stat.wisc.edu/~reinsel/stat324
Examples of useful commands include: 
summary(rainfall),  boxplot(rainfall),  mean(rainfall),  var(rainfall),
u <- log(rainfall), u <- sqrt(rainfall), u <- rainfall^(1/4), qqnorm(u),
plot(rainfall,u), and so on
In general, you can view the symbol "<-" as an `assignment' symbol.

Then you need to save the plot. The commands below can be used
either in Linux or Windows to save the plot as an .eps file:

> postscript("plot.eps", horizontal=F, width=5, height=5)
> qqnorm(ex04.83$thickness)
> dev.off()

Or you can change plot.eps to plot.ps, you can save the plot as a .ps file.

In windows, you can save the plot to other forms of files: click the plot,
then click the menu File -> Save as ... you can save it to other forms.

Additionally, you can use

> help.search(".....")

to search things you want, just input the key word in .....place.

You can also use

> help(lm)

to get information about the functions(here lm is just an example function).
Type "q()" to quit R, that is,

> q()