University of Minnesota, Twin Cities School of Statistics Stat 3011 Rweb Textbook (Wild and Seber)

We will be using computers in the course. The default statistical computing package will be R and its web interface Rweb, which can be used in any web browser. You are permitted to use any other computer statistics package with which you are familiar and we can have installed in the computing lab (so you can use it for tests), but the instructor and teaching assistant may not be able to help you with it.

R is a general purpose computing language designed especially for statistics. You can do any computational problem in R, but what it is really good at is statistics.

R is free software (both free as in "free beer" and free as in "free speech"). If you want to use it at home, you can download it from CRAN (the Comprehensive R Archive Network). It is available for Microsoft Windows and all versions of UNIX (including Linux). A Macintosh port is there but may be tricky to install. You do not have to download R if you don't want to. R is installed in the computers in the lab (Room B53, Ford Hall), and R can be used over the web on any computer that runs a web browser (see the section on Rweb).

The textbook describes doing statistics using a variety of software packages. In addition to R, it also describes three other software packages, S-plus (which is a proprietary package very similar to R), Minitab, which is a proprietary package, quite different from R, and Microsoft Excel (a spreadsheet program).

We do not insist that you use R (or Rweb), but we will only teach the use of R (and Rweb) in the lecture and labs. If you already know some other package and think you can use it for homework and tests, go ahead (though perhaps you should discuss it with the instructor).

Because R is free software, it can be made to run over the web.

Many examples we will use in this course are inserted right in the web pages. For example, clicking on the "Submit" button below runs Rweb to draw a histogram just like Figure 2.3.8 (p. 56) in the textbook (Wild and Seber).

After you've looked at the histogram, use the "Back" button on your browser to return here.

Don't be put off by the complexity of the R command typed in the box. Most histograms we draw, use much simpler code, like

After you've looked at the histogram, use the "Back" button on your browser to return here.

Homework problems and lab exercises will generally be a little harder in that you have to find the data (these examples automagically load the right data set). But that's not much harder.

To try using Rweb the way you would for a homework problem, go to the Rweb page especially for this course and try the example explained at the bottom of that page, which makes the same histogram as the first example above.

Note that this link is on the menu at the top of most of the course web pages.

There is another Rweb page for general use, but we won't use that.