A sas array is a set of variables of the same type, called elements of the array, that you want to perform the same operation on. Do is an acronym as well, standing for domain object, digital output, digital order, data operation, data only, and device object. In this example, we will create 3 records for each value of id, where id is a number from 1 to 4. The iterative %do defines and increments a macro variable. If you are used to conditionally processing statements in a doloop in sas, there is no real substitute for that in stata. How can i generate pdf and html files for my sas output. Today is the first anniversary of this blog, which is named the do loop, so it seems appropriate to blog about do loops in sas. Running sas code on multiple files with do loop and a. List all files within a directory including subdirectories tree level 3.
I am very new to sas and have received my first work assignment. With sas, you use statements to write a series of instructions called a sas program. The iterative % do defines and increments a macro variable. Sas macro do loop import multiple flat files stack overflow. But when you want the same set of statements to be executed again and again, we need the help of loops. One way to overcome the inefficient use of time, manpower, and computer processing is to use sas arrays and do loops. Sas macro do loop import multiple flat files stack. The program communicates what you want to do and is written using the sas language. Multipage pdf documents can be displayed as a presentation, similar to a microsoft powerpoint, where the pdf automatically progresses each page as well as being able to loop the presentation. Use the rank function to return the position of a character in the ascii or ebcdic collating sequence. All of the files have the same data step, so im trying to write a do while loop to import all the files.
Mar 30, 2020 dofile is also a function used when compiling and executing lua programming code, but it isnt related to the. Data statement sas statements do statement iterated sas statements end statement sas statements run statement do loop processing you can use do loops to perform repetitive calculations. The outest option saves the parameter estimates in a data set. Working with finance data in sas justin mccrary professor of law and dlab director, uc berkeley faculty research associate, nber dlab workshop tuesday, january 27, 2015. The do loop because arrays are easily referenced with an index value, they are very often used with a do loop. A macro for reading multiple text files debbie miller, national park service, denver, co abstract most of us have to exchange data at some time or another with others who do not use the sas system, and therefore cannot use or send sas data sets. Import all csv files that exist within a directory. Do loop processing do loop processing statements within a do loop execute for a specific number of iterations or until a specific condition stops the loop.
From my research, i believe i need a macro with a do loop that will run this search for all of the files. I end up with files such as main file, temp1, temp2, temp3, temp4, temp5, temp6, temp7, temp8 and temp9. What is the best way to loop through each file and create one big file or a dataset per file to get the total number of rows across all files. What sas statements would you code to read an external raw data file to a data step.
A macro to produce a sas data set containing the list of. If i do it the way in the code above, only the last loops results are saved in each of the files, because every iteration overwrites the previous one, instead of appending to the bottom of it. Exporting to multiple pdf files in a loop by appen. Extracting data from pdf files nat wooding, dominion virginia power, richmond, virginia. An easy way to run thousands of regressions in sas the do loop. I have a list of 17 flat files that im trying to import into different data sets. You can reshape the data using proc transpose or reshape the data in a data step. Ill describe looping in the sas data step and compare it with looping in the sasiml language. This paper presents a number of examples to demonstrate how to take advantage of the %do loop to build sas statements dynamically.
Only when this file exists, excel will convert it to pdf files and place the newly created pdf file into folder d. I know gtl at least ive heard of it, not that i have great experience in this area but i agree that for this example might be a bit overkill i would rather do it manually i looked at your code and i see that you used the put function. The following will illustrate how to reshape data from wide to long using the data step. The sas statements are repeatedly executed until the final value of the index variable is. A sas macro to automate importing excel worksheets into. Fortunately, there is a more efficient alternative.
The main difference between the do while and do until loop is that the do until expression is evaluated at the bottom of the loop while the do while is evaluated at the top of the loop. I want all regression outputs to be in pdf file 1, all print outputs in pdf file 2 and all plot outputs in pdf file 3. Do while loops continue executing while the condition you have specified remains true. Looping through files in a directory sas support communities. How to increment a macro do loop by a noninteger value.
We did not have success opening these files in other browsers. Dec 05, 2019 use the rank function to return the position of a character in the ascii or ebcdic collating sequence. You can include any number of exit do statements anywhere in a doloop. Arrays and do over loops are a way of programming more. So the problem is that sas does not treat subsequent values of i as numbers but as text. I have an excel file in which i have a macro that creates a series of pdf files via the activesheet.
Running sas code on multiple files with do loop and a macro. This macro will run a do loop creating state twodigit abbreviations, which will allow a simple way to read the summary files into sas for all geographies. Accessing data, creating data structures, managing data. A powerful technique for combining and aggregating complex data renu gehring sas instructor health care analyst acecube, llp careoregon, inc. The until expression is evaluated after the statements in the do loop have executed, and the while expression is evaluated before the statements in the do loop have executed. The other type of do loops that you can run in a sas data step are conditional do loops. What i would like to do now is combine these files into a single file with the same name as the main file. How to use character values on a macro %do loop sas. Sep 07, 2011 today is the first anniversary of this blog, which is named the do loop, so it seems appropriate to blog about do loops in sas.
Depending on the problem you are trying to solve, one of statas looping commands. More advanced macro techniques after mastering the basic techniques discussed earlier in this chapter, you may want to learn some more advanced macro techniques. Given below is the general form of a do loop statements in sas. The first type of do loop uses a list either numeric or character and the loop is executed once for each value in the list specified in the do loop. Together they allow us to iteratively process large amounts of data with a minimum amount of code. Do until loops continue executing until the condition you have specified becomes true.
When used within nested do loops, exit do transfers control out of the. The sasiml language is a matrixvector language, so statements that operate on a few long vectors run much faster than equivalent statements that involve many scalar quantities. Example 3 nested do loops when a do loop is iterating within another do loop, it is known as a nested do loop. Generating repetitive pieces of text using % do loops.
In the case of these files, i could not used a macro. A macro to produce a sas data set containing the list of file names found in the requested windows or unix directory mike goulding, experis, portage, mi, usa abstract clinical programmers often need to perform a particular process for each file that exists in a specific directory, on windows or unix. The iterative % do is very similar to the do statement used in the data step, but it is not confined to the data step. In previous examples, the % do loop is used to generate single sas statements. Nested do loops are easier to understand with a simple example. Top 50 sas interview questions for 2020 sas training edureka. One use of exit do is to test for a condition that could cause an endless loop, which is a loop that could run a large or even infinite number of times. Sas enhancements, above, the whilecondition is evaluated at the top of the loop, test2, line 5, whereas the untilcondition is evalu ated at the bottom of the loop, test5, line 10. An alternative way to analyze those regression models is to transpose the data to long form and use a bygroup analysis. Importing data files that are not in sas format into sas and compiling them for. A vba macro to convert all rtf files within one folder. Ill describe looping in the sas data step and compare it with looping in the sas iml language. The code in this section generates files that can be opened in internet explorer. The sas iml language is a matrixvector language, so statements that operate on a few long vectors run much faster than equivalent statements that involve many scalar quantities.
In this sas tutorial, we will explain how you can learn sas programming online on your own. This paper presents a number of examples to demonstrate how to take advantage of the % do loop to build sas statements dynamically. The %sysfunc function is needed to use sas functions within the macro facility. Running sas code on multiple files with do loop and a macro i am very new to sas and have received my first work assignment. Generating repetitive pieces of text using %do loops. Do loop, do until, dow loop, array statement, dim function, set statement options introduction although most sas data step programmers have made use of do loops and arrays, few take full advantage of. Sas will then progress on to the code you typically use to process the file. You can join our sas base certification training program free of charge. Tasks 1, 2 and 3 each produces some output i would like to save in 3 separate pdf files. Vba macro will enable excel to loop through all nonblank cells in column a except for cell a1 until all files are converted.
I have some advice on using do loops in sasiml language. Learn how to use doloop, dowhile and dountil in sas. Sep 07, 2011 i have some advice on using do loops in sas iml language. Beaverton, or portland, or abstract the use of multiple set statements in a data step is little known and often misunderstood. List all files within a directory including subdirectories. Proc import combined with % do loop to read in the data from multiple excel worksheets. You can aggregate the statistics by using proc append or the data step. An easy way to run thousands of regressions in sas the. Carpenter california occidental consultants, anchorage, ak abstract do loops and array statements are common tools in the data step. The result is that a do until loop will always execute at least. A vba macro to convert all rtf files within one folder into. The iterative %do is very similar to the do statement used in the data step, but it is not confined to the data step.
Reshaping data wide to long using a data step sas learning. Lets say you have a series of sas data sets class1 class10 that contain students math scores and you want to calculate the average scores for each of the ten classes. Sas do index loop this do index loop uses a index variable for its start and end value. The difference between while and until is obfuscated by their placement at the top of the loop construct. To do this you first need to create your standard pdf document and then configure adobe reader to progress automatically and loop when in full screen mode. Creating sas data sets from input files that contain raw data external files creating new sas data sets from existing ones by subsetting, merging, modifying, and updating existing sas data sets analyzing, manipulating, or presenting your data computing the values for new variables report writing, or writing files to disk. Again, we run a regression model separately for each of the four race categories in. Mar 22, 20 multipage pdf documents can be displayed as a presentation, similar to a microsoft powerpoint, where the pdf automatically progresses each page as well as being able to loop the presentation. It can also be used to dynamically build a series of data steps or proc steps. Whether you need to iterate over parameters in an algorithm or indices in an array, a loop is often one of the first programming constructs that a beginning programmer learns. A beginners guide to arrays and do loops sas institute.
Do you know that the sas certified specialist exam now requires you to write and execute code in the exam. I then wrote a simple loop and put statement routine that created and stored a years worth of macro calls. Use the %do statement to loop through the entire directory based on the number of members returned from the dnum function. Learning by doing is the best way to master a programming language.
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