Therefore, %str and %nrstr are useful for masking strings that are constants, such as sections of sas code. Macro functions call symput macro var, charactervalue call symputx macro var, charactervalue assigns a value to a macro variable during execution of data step call symputx. In this course students will learn the syntax of sas macro, see the use cases and will go through some workout examples. In macros, we can write functions inside or outside of the macroblock global function. Sas macros for faster data manipulation complete tutorial. Beyond these basic, and most commonly used examples there lies a world of macro. Below is a table of macro functions, their inputs, and a description of the function sas institute inc. Manipulate values of sas variables manipulatevalues of macro variables executed when the data or proc step in which they are included is executed executed at word scanning time by the macro processor over 500 available in sas 9. In the below example the value of the variable today is written to the program log.
Macro programming is generally considered an advanced topic. In order to run this macro, your program must know where nd it. This paper is designed for people who know the basics of sas programming, but know nothing about sas macro programming. Use macro logic to determine if an external file is empty tree level 4. Using this function, we can report length of the macrovariable. The sas macro and r function pseudoci provide pseudovalues for the cumulative incidence function for competing risks data. This chapter introduces the sas macro facility using simple examples and explanation. For macro character functions that have a q form for example, %scan and %qscan, the two functions work alike except that the function beginning with q masks special characters and mnemonic operators in its result.
Implementing unionfind algorithm with base sas data steps. Programming language for string manipulation strings are characters usually sas statements or pieces of sas statements normally considered advanced, but concepts are not difficult. Writing cleaner and more powerful sas code using macros. It represents the sas code file which can be edited using the sas editor or any text editor. Macro function for accessing operatingsystem parameters macro functions for names of stored results macro function for formatting results. Furthermore, the situations for utilizing macro quoting functions are not obvious for programmers. Using sql within sas, author howard schreier illustrates the use of proc sql in the context of the sas data step and other sas procedures such as sort, freq, means, summary, append, datasets, and transpose whose functionality overlaps and complements that of. It has some conflicting approaches to other parts as being a programming language on its own. In a macro for example, in the %sysfunc function, fileref is the name of a macro variable without an ampersand whose value contains the fileref to assign to the external file. For example, a data step will be compiled and executed, then a procedure step will. Call symput in sas explained with examples data science. Sep 17, 2020 example when the value contains a data step expression. Data step or case proc sql statement, create an exception tier.
Macro functions manipulate arguments within the context of the macro language. A sas macro returns text that is inserted into the processing stream. For example, the input function can be used to return a numeric value back to the user based on a character value and a valid sas format. Blanks are not removed from value before assignment to macro variable call symputx. A new sas macro for flexible parametric survival modeling. Sas code will be provided and finally examples of using the sas macro. Macro variables are character variables so the %eval function may be required. Also, read the date interval functions intnx and intick in sas.
To help in tracking the macro code as well as the sas code generated by the macros, some system options can be used. Define sas macro as a function and syntax of loop inside sas. For example a common usage of %sysfunc is to get the current date and time via the today and time functions for placement in a report footnote. It includes useful tips and tricks of sas macro programming and outlines real world examples of automation with sas macros. Sas introduction and selected textbook examples by sas code for survival analysis using s. How to create and use sas macro functions sas users. How a macro program is compiled 114 how a macro program executes 120. These sas macro functions have similar syntax, compared to their counterpart functions in data steps and they also return results in a similar manner. Advanced techniques, offered in the classroom, as live web classes, or as selfpaced e.
This means by the time the macro executes, the string is already masked by a macro quoting function. In section 2 we present a summary of the statistical background for these regression models. However the reason for calling them functions rather than macros is because they are used in a way which is not the norm for traditional sas macros. This paper will discuss such functions and provide examples of their use. Through this implementation, we will demonstrate an elegant solution to find and group connected components in complex networks stored in a sas data set. Macro functions before tackling how an arrays and macro variables come together to form macro variable arrays, knowledge of useful macro functions is vital to comprehending all of the aspects of more dynamic macro code. Sas code you will learn the syntax, to detect number of variables in a datasetcreate loop to run for all the variables of a datasetdetect number of distinct. In general, a macro language function processes one or more arguments and produces a result. Executing sas functions with the %sysfunc macro function. This section describes the features of the sas macro facility that are new or enhanced since sas 8. Sas tutorial for beginners to advanced practical guide. You can tell sas where to nd macros by using the options mautosource sasautos macros are located. Many sas data step functions like put have macro analogs. The macro facility uses statements and functions that resemble those that you use.
In this example, the macro variable named holdate receives the value july 4, 1997. The macro language functions are listed in macro functions. I have multiple programs in a project, and the final programs will reference this macro global to identify if there is an exception, and depending on the either the select. When the above code is run we get the following output. Create your own functions using sasmacro and scl lexjansen. Returns is absolutely an appropriate term for that. The number of functions included in sas software has exploded in recent versions, but many of the most amazing and useful functions remain relatively unknown. Supplementary data 1 describes the input sas dataset and supplementary data 2 details parameters and macro call set up using the sas code with further descriptions to help the user. In macros, we can write functions inside or outside of the macroblock global function a % length. Note that you resolve this sas macro variable the same way we did in our %let discussion above. But, while macros certainly can be challenging, it is also true that the basic concepts are not difficult to learn. We use this function to convert the case of letters to uppercase. After doing the course students should become comfortable in writing sas macros. Oct 16, 2017 be sure to save your userdefined %format function in your stored compiled macro or autocall library for convenient reuse.
Sas programs are usually made up of a number of data or proc steps in order to process data. For example, at the channing lab, as described on chandoc. Define sas macro as a function and syntax of loop inside. If you enjoyed this tip on how to format a macro variable in sas, and want more like it, consider taking our sas macro language 1. Macro functions include character functions, evaluation functions, and quoting functions. Implementing unionfind algorithm with base sas data. Dynamically determine the number of observations and variables in a sas data set tree level 4. Why arent sas macro variables localscope by default. The sas programs, data files and the results of the programs are saved with various extensions in windows.
Using sas macro functions to manipulate data lexjansen. Sas macros sas macro is used to automate the repetitive tasks i. Both new and experienced sas programmers should find something new to add to their toolboxes. For the following example, the files have been saved in c. Therefore, %str and %nrstr are useful for masking strings that are constants, such as sections of sas. Proc sql can create sas macro variables that contains values from a query result. I would be willing to bet there are tons of bugs out in the sas wilderness due to this design choice. It can never return a value, though in some cases you can mimic functions. A macro language function processes one or more arguments and produces a result. Sas macro sas macro has a long history of being used as the major alternative for userdeveloped functions. The value returned by the expression in the current observation is assigned as the value of macro variable. You can use all macro functions in both macro definitions and open code. In section 4 we present an example of the macros and functions.
We explain how the macro processor works, and how to. For example, a good exercise would be to make some transformations of the output. Since the sas macro facility stores all values as a text string, there may be times when you want to. Arrays are valid only in the context of the data step, so theyre not available here. This example stores three words in the macro variable. Sas macro functions there are some sas macro functions which help you to execute various operations within a macro. If the function is used within a data step, the fileref must be enclosed in single quotation marks. Call symput in sas explained with examples data science central. Functions that create sas date, datetime, and time values the first three functions in this group of functions create sas date values, datetime values, and time values from the constituent parts month, day, year, hour, minute, second. The correct bibliographic citation for this manual is as follows. It represents the sas log file it contains information such as errors, warnings, and data set details for a submitted sas program. According to sas marco language reference, the macro facility is a tool for extending and customizing the sas system and for reducing the amount of text you must enter to do common tasks. The sas code for the macro suite is available from the. The most common uses for macro variables are as data file names or targets of logicalif statements.
Do not alter these files, but move them to a folder directory that sas can access. Before we go into the scope of macro variables, it is important to look at some examples. Sas macro while i am calling the code i will be creating functions they are technically sas macros. In the following example we create a macro variable called w55, which contains the number of students whose writing scores are higher than or equal to 55. Using sas language functions in the data step and macro facility. Introduction to the sas macro facility dartmouth area. Macro variables that contain entire sections of a sas program can also be created with the use of the str macro function. The message that will be generated by these system options can be seen in the sas log. Example to illustrate the problem, first let us introduce a simple example in table 1, where we are trying to find all linked. Will resolve to the proc means step running every time the sto2 macro variable is invoked.
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