Features of IMLPlus Programs

IMLPlus programs such as the one that created Figure 1.2 share certain features. They typically include the following steps:

1. If the data are not already in a SAS data set in a library, put them there (Chapter 2).

2. Call a SAS procedure (Chapter 4).

3. Read in results produced by the procedure (Chapter 5, Chapter 6, and Chapter 7) and, optionally, use SAS/IML statements for additional analysis.

4. Create graphs that use the results (Chapter 3, Chapter 5, and Chapter 6).

5. Customize attributes of the graphs (Chapter 8, Chapter 9, and Chapter 10).

The chapters of this book describe these steps in detail. Later chapters build on earlier chapters. The last chapter (Chapter 11) discusses calling functions in the R language.

In each chapter, you write a short program that illustrates a few key ideas. You should type the program into the program window. You can create a new program window by selecting File New Workspace from the main SAS/IML Studio menu. For your convenience, the program for each chapter is also distributed with SAS/IML Studio.

The remainder of this chapter discusses concepts that are useful in IMLPlus programming but might not be familiar to the average SAS programmer.

• IMLPlus programs use classes and methods to manage dynamically linked graphs. The section Understanding Classes, Objects, and Methods explains these concepts in general, and the section The DataObject Class focuses on a class that is particularly important in SAS/IML Studio.

• IMLPlus programs that call SAS procedures require transferring data between an in-memory version of the data and SAS data sets. The section Where Are the Data? introduces this concept. Chapter 2, Reading and Writing Data, discusses it in detail and gives examples.