S and S-Plus: An Eclectic Tour of the Environment

The context and background of this paper is a workshop where exponents of several software systems for data analysis and data visualisation presented their products for comparison. The style of data analysis best supported by S-PLUS begins with an initial inspection and exploration of the data, largely graphical, a model building and fitting phase, guided by the problem context and the data, usually with several different models, followed by a diagnostic checking of the results and re-examination of the earlier phases as necessary. My purpose is not to give a complete description or even a complete overview, but to present S-PLUS in action through several small but typical and hopefully easily appreciated examples, as a person sitting at the terminal would view the system, or at least the sequence of impressions and steps such a person might take.