SAS宏_经典教程_2007年第二版_

This book is for beginning through experienced users of SAS who want to learn about SAS macro programming. It assumes that you have beginning to intermediate experience writing SAS language programs, and it does not review SAS language and SAS programming concepts. The focus of this book is to make the macro facility a tool you can use in your programming. It is less inclusive and spends less time on reference details than SAS Macro Language: Reference. The technical aspects of macro processing are described in this book. While understanding the technical aspects is not necessary to begin to reap the benefits of the SAS macro facility, this knowledge might help you more wisely apply macro programming techniques. Don't worry if the technical aspects are difficult to grasp at first. Instead, jump in and start using the simpler features of the macro facility. Try macro variables first. You're bound to make some errors, but those errors help you understand macro processing. Eventually, as your macro programming skills improve, a more thorough understanding of macro processing can reduce the number of macro programming errors you make and make it easier to debug your programs. This book is grouped into three parts. The first part explains the elements and mechanics of the macro programming language. The second part shows ways of applying your knowledge of macro programming that you gained in the first part. The third part contains four appendixes that provide a quick reference to the macro language, the data set used for most of the examples, and a short description of the example programs. This book starts with the easier features of the SAS macro facility. These features are building blocks for the later topics. The features of the macro facility are interrelated, and so occasionally you might see some features used before they are formally discussed. Because macro facility features are interrelated, this book does not have to be read in a linear fashion. Work through sections as appropriate for your needs. Return to earlier sections when that information becomes pertinent. However, it is best to start with the technical information in Chapter 2 and move on to the macro variable chapter, Chapter 3. You might then work with macro variables extensively and try some of the features like macro functions and macro expressions that are described in Chapters 6 and 7. After