S-PLUS Applications and Links

S-PLUS is a powerful interactive package for statistical and graphical analysis. It is a combination of an object-oriented programming language, powerful graphics capabilities, and a large number of pre-programmed statistical routines. The programmability of S-PLUS gives it extreme flexibility, which is why it is very popular with statistical researchers. However, this flexibility can be intimidating to the first time user.

While this page cannot provide a complete tutorial on using S-PLUS, it does cover the basics of starting S-PLUS in a Unix environment, such as VET, and a quick-start guide to on-line help in S-PLUS. Also included are pointers to more information, on the web and elsewhere, about S-PLUS.

One particular web resource will be pointed out here: Notes on S-PLUS by Bill Venables and David Smith is a Postscript file containing an 87 page tutorial on S-PLUS. This is probably a good place for the novice to start.

Using S-PLUS on VET

The normal mode for S-PLUS is an interactive, or command-line format, where each command is typed and the user waits for the results. There is a ``batch'' mode, where a file containing a list of commands is executed ``in the background'', but this is not covered here. More information about this can be obtained by examining the help inside S-PLUS on ``BATCH'' (see below for more information about the S-PLUS online help).

To start the S-PLUS interactively on VET, the simply type

% Splus

To get graphics in S-PLUS, a ``device'' must be initialized. In X (X-windows), the easiest device to use is the Motif device. To start this device, simply type the command

motif()

S-PLUS has extensive help on all of the built-in functions and datasets. In X-windows, a window-based help utility is started by issuing the command

help.start()

• The list of functions has a line for each function, which includes the function name along with a short description of that function. Any line can be clicked on with the left mouse button, and a separate window will pop up with the help for the function listed on that line.
• The list of categories contains a list of topical categories. Clicking on one of these lines lists the functions that pertain to that category. For example, clicking on the category ``Regression'' displays a list of functions that deal with different kinds of regression.
• The topic entry window allows the user to type in any string and click the ``Enter'' button (or hit return) to display a list of functions that have that string in their name or in their short description.

help("lsfit")

Electronic Resources on S-PLUS

Because of its heavy use in academic statistics community, there are many web-based resources on S-PLUS. A small segment is given here, highlighting the sites that are deemed most useful.

Books on S-PLUS

While not an exhaustive list of books on S-PLUS, this list covers the main introductory texts on S-PLUS. Each book has a slightly different approach, often relating to the approach to statistics that the authors take.