How to use character values on a macro %do loop sas. How a macro program is compiled 114 how a macro program executes 120. Sas is rich in various builtin functions, and predefined sas supplied macros. Sas tutorial for beginners to advanced practical guide. Then, we will develop macro coding examples to explore macro variables macro functions macro definition macro programming statements. Another way of creating macro variables is through proc sql.
For more information about evaluation of expressions by the sas macro language, see macro expressions. 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. If nc is omitted or equal to zero, the value returned is from the central t distribution. Macros macros consist of collections of regular sas program statements, macro variables, macro language statements, and macro functions contained within a % macro and a %mend. Carpenter, california occidental consultants abstract many macro functions are very analogous to those of the data step.
Basic macros rely on symbolic substitution to place values in particular locations in sas codethey simply create code. You can use all macro functions in both macro definitions and open code. Sas macro provides an incredible way to make a process easy and automatic. Some sas statements consist of more than one line of commands. Sql stands for structured query language and is a standardized database language. This tutorial explains sas macros with practical examples. May 01, 2019 sas macro provides an incredible way to make a process easy and automatic.
By default, autocall facility is enabled in the sas system. Heres a sas macro to create and remove a pc directory. Knowing sas macros is an advantage in the job market over other candidates. The macro language functions are listed in macro functions. The %sysget function returns the value as a character string. This example works if you use %str, but it is not robust or good programming practice. The sas macro facility is very useful for text substitution and for generating repetitive statements, but what you envision doing requires an understanding of the difference between macro compile time, macro execution time, data step compile time and data step execution time and what happens during each phase of the process.
It receives only the results of these functions because these functions work when a macro compiles. If argument contains a comma, enclose argument in a quoting function, for example, %quoteargument n is an integer or a text expression that yields an integer, which specifies the position of the word to return. Upon completion of this tutorial, you would understand how to create macros and where they can be used. Use the rank function to return the position of a character in the ascii or ebcdic collating sequence. Aug 02, 2012 sas macro functions %eval and %sysevalf the %eval function evaluates integer arithmetic or logical expressions. This function will be added to the conversions package along with the function lb2kg created in example 1. The macro language functions are listed in the following table. The collection of functions and call routines in this chapter allow you to do extensive manipulation on all sorts of character data. Structured specifically around the most commonly used statistical tasks or techniquesfor example, comparing two means, anova, and regressionthis book provides an easytofollow, howto approach to statistical analysis not found in other books. Sas provides some builtin macros which will be stored in the sas installation folder \9.
Sas macro to split a macro variables values to multiple macro variables values and also get the split count into another variable. Mastering this facility will enable the novice user to become an accomplished programmer. Dec 22, 2015 sas macros are useful when we want to execute same set of sas statements again and again. Calculate average height and store in a macro variable. If argument might contain a special character or mnemonic operator, listed below, use %qscan. The %sysfunc function is needed to use sas functions within the macro facility. Valueis a character variable informatis a sas is a sas informatinformat, defines the input format of, defines the input format of value putvalue, format performs numeric totocharacter conversion. 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. A sas statement may continue over more than one line. The terms compiletime and runtime should be understood as related to macro for mastery of macro quoting functions. Nov 21, 2019 the behavior of the %sysget macro function is specific to windows. Dec 05, 2019 the %substr and %qsubstr functions produce a substring of argument, beginning at position, for length number of characters.
The function is used just as you would any other sas function. Macro functions include character functions, evaluation functions, and quoting functions. While data step functions are applied to values on the program data vector, pdv, macro functions are used to create, modify, and work with text strings. 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. Often we ignore notes and warning in the sas log when we try to createremove a directory that doesdoesnt exist. This function accepts noninteger degrees of freedom. Selected autocall macros provided with sas software tree level 3. Sas macro quoting functions also are used to mark starting and ending delimiters. For functions, the number of arguments can vary whereas comparison operators are nested between two operands. What if you had two groups of statements that you commonly used to put observations into groups based on a variable named age. Special functions inputvalue, informat performs charactertotonumeric conversion. Therefore, %str and %nrstr are useful for masking strings that are constants, such as sections of sas.
In sas statistics by example, ron cody offers up a cookbook approach for doing statistics with sas. The %sysevalf function evaluates arithmetic and logical expressions using floatingpoint arithmetic and returns a value that is formatted using the best32. The macro processor uses evaluation functions to do the following. Sas macros for faster data manipulation complete tutorial. Examples will include functions like %sysevalf and %sysfunc, which are new to v6. If the uppercase value of the response is dec, then proc fsview runs on the data set reports.
If the argument to the %sysevalf function contains no operator and no conversion type is specified, then the argument is returned unchanged. The values of a date variable represent the number of days. Functions both encapsulate and raise the level of abstraction of the code contained within it. This is an ideal case for use of macro rather than typing copy pasting same statements. In the following example we create a macro variable called w55, which contains the number of students whose writing. Both windows and sas environment variables can be translated by using the %sysget function. A sas macro to automate importing excel worksheets into. Abstract the macro facility is an important feature of the sas language. If the function is used within a data step, the fileref must be enclosed in single quotation marks. One convenient checking tool is the in operator that has been extended in 9. The pdf function for the t distribution returns the probability density function of a t distribution, with degrees of freedom df and noncentrality parameter nc, which is evaluated at the value x. Returning a character value by default functions work with numeric values.
Reference %unquote macro function during macro execution, unmasks all special characters and mnemonic operators for a value. 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. Macro functions macro functions operate much as regular sas functions, except that the arguments are within the context of the macro language. New automatic macro variables the following are new automatic macro variables. In this paper, we will walk through the various types of functions, macros, and how the functions and macros are stored and processed internally. It includes useful tips and tricks of sas macro programming and outlines real world examples of automation with sas macros.
Below program gets us all the observation of the make audi and type sports. Then, they perform the operation specified by the operand and convert the result to a character value. We developed a simplified but robust approach for text analysis using a combination of 3 simple sas string functions namely index, indexw and soundex in base sas macro environment. A simple approach to text analysis using sas functions. Macro functions are fun to write, they reduce the possibilities of macro variable collisions, and best of all, they can be used to impress your date after the movies. Writing cleaner and more powerful sas code using macros. Proc sql can create sas macro variables that contains values from a query result. The %sysfunc and %qsysfunc functions enable most of the functions from base sas software, a function written with the sas toolkit software, or a function created using the fcmp procedure available to the macro facility. It will help the novice sas user bridge the gap between beginner and expert programmer.
This macro first checks for the existence of the directory and then createdelete it or else put a message to the sas log. Import all csv files that exist within a directory. A macro language statement instructs the macro processor to perform an operation. Since the sas macro facility can be perceived as mysterious until you understand the inner workings, we will begin by exploring common gotchas to help you avoid some traps. A macro language function processes one or more arguments and produces a result. The %substr and %qsubstr functions produce a substring of argument, beginning at position, for length number of characters. A listing of sas supplied functions can be found in any version of the sas language reference dictionary manuals whereas userdefined functions are only available in the sas macro language. Valueis a character variable informatis a sas is a sas informatinformat, defines the input format of, defines the input format of. In this example, the macro runrept compares a value input for the macro variable month to the string dec.
Here, we will see different sas macro variables, functions of macro in sas programming language. Macro variables are character variables so the %eval function may be required. 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. How to increment a macro do loop by a noninteger value. References burlew, michele, sas macro programming made easy, cary, nc. They temporarily convert the operands in the argument to numeric values. Valueis a character variableis a character variable.
Evaluation functions evaluate arithmetic and logical expressions. Keywords macro, macro functions, %sysfunc, macro quoting, scl macro character functions macro character. Sas datetime informats are able to convert raw data into a date, time or datetime variable. 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. Node 6 of 7 node 6 of 7 selected system options used in the macro facility tree level 3. Moreover, we learn components of sas macro code and some benefits of sas macro. List all files within a directory including subdirectories. This means by the time the macro executes, the string is already masked by a macro quoting function. Key concepts a sas date, time or datetime variable is a special case of a numeric variable. Macro is a group of sas statements that is identified by a name and to use it in program anywhere, we can reference it with that name.
Dec 05, 2019 use the rank function to return the position of a character in the ascii or ebcdic collating sequence. Sas macro programming is considered as an advanced sas. Here the value field can take any numeric, text or date value as required by the program. If the value is truncated or the variable is not defined on the operating environment, %sysget displays a warning message in the sas log.
The date and today functions are equivalent and they both return the current date. The differences and timing of the compiletime macro quoting functions, %str and %nrstr, will be emphasized. We will introduce interaction between macros and regular sas language, offer tips on debugging macros, and discuss sas macro options. In general, a macro language function processes one or more arguments and produces a result. It consists of a string of keywords, sas names, and special characters and operators, and it ends in a semicolon. The differences are in how they are used and applied. However, their usage by general base sas users is precluded by affordability, availability and flexibility. Character functions 3 introduction a major strength of sas is its ability to work with character data. However it is possible for a function to act on character strings and to return character values. Similarly, functions and macros can also be developed by user based on his needs and requirements.