So, by the time the code goes to be executed against your data, there are no macro statements left in the code. Table 16. The noequals option tells SAS not to preserve this order, making the sort more efficient. For example, if VAR=X and Num=1, then your %IF test would seem to be asking this of the macro processor, as if the macro processor has visibility of the DATA step his comment is here
Coding to eliminate division by 0 error messages Needs improvement More efficient data election; set in.elect; rvotepct = 100 * (rvote/tvote); run; data election; set in.elect; if (tvote gt 0) then Test syntax before executing You can test for some basic problems in your code by compiling your program without executing. Coding to eliminate missing value error messages Needs improvement More efficient data election; set in.elect; sortkey = state*100 + district; run; data election; set in.elect; if (district > . ) then This problem has been remedied in Stat/Transfer Version 8 and above. More Bonuses
In most cases, absolute efficiency gains will be rare. You can then sort these subsets by additional variables and concatenate the subsets to get a data set sorted by the variable you used to subset the data. Deleting a data set with Needs improvement More efficient proc reg data=newdata; [model statement] run; ** continue with rest of program **; * without using work.newdata **; * again. **; proc Human resources Human time and effort are also important resources, and come into play both in the development of a SAS program and in maintaining or extending a program for future
The class statement also lets you preserve the order of the input data set for later use. If you use the special data set name _null_ in the data statement, no data set will be created. Some examples: You can also use the label= data set option to label permanent SAS data sets, providing information about the sort order or the purpose of the data set: Separate Using a class statement (in procedures that allow it) produces the same results as a by statement and uses less CPU time than the combination of proc sort and the by
Optimizing efficiency with respect to one resource will often decrease efficiency with respect to some other resource. Sas Divide By Zero Please Note! Grouping constants together Needs improvement More efficient total = .242 + x + 5 + y; total = x + y + .242 + 5; Use a series of if statements Check This Out Table 17.
This will ensure that you always know what data set you are working with. For example, instead of using: consider using Also, use parentheses and blank space to make your comparisons easier to read. The %IF statement gets evaluated when the SAS Macro program is executed, but the SAS Macro facility is only generating code that will be executed. One structure might look like: Specify data set names Always specify a SAS data set name in data and proc statements.
In addition, use comments within your program. https://groups.google.com/d/topic/comp.soft-sys.sas/0eegpXE7O98 Plan your program carefully before writing the code; use a flow chart to map out what you expect to happen and in what sequence. 1. Division By Zero Detected In Sas See the attached screen shot. Sas Divide Function Always review the log after submitting a job; at times you may not be able to tell from the list file output that SAS failed to complete its job.
Use other techniques to emulate large sorts Sometimes a data set is too big to successfully execute proc sort. this content Each place is given by: (Number of times) at (Line):(Column). 1 at 18:26 A report listing the data will simply show that the values are missing. Memory: the amount of the computer’s memory required by your program. Avoid confounding factors in the code, the working environment, and the SAS session.
Using the command to reduce processing time Needs improvement More efficient data testdata; set mydata; if _n_ le 100; run; proc print data=testdata; run; ** print the first 100 obs **; Pay attention to messages about uninitialized variables and missing values. Say that you used Stat/Transfer to make a SAS data file called c:\mydata\hartman.sas7bdat and you go to use it in a statistics procedure (in our example, proc reg) like below proc http://darrenmanning.com/by-zero/division-by-zero-error-in-vba.html For example, if you have simple data like this:grp x1 x2 x3 x4 x5AAA 5 10 15 . 25BBB 3 . 11 13 17CCC 4 5 . 9 11and you want
Plan for unknown data When handling your data, anticipate when variables will take unexpected values. Table 3. By decreasing the amount of I/O time used, you can often dramatically improve the execution speed of your program.
Table 2. Eliminate temporary data sets Needs improvement More efficient data newdata; set in.mydata; run; proc reg data=newdata; [model statement] run; proc reg data=in.mydata; [model statement] run; If you want to look at This is particularly true if your program does more data manipulation than complicated statistical estimation. This enables anyone to see at a glance what is going on in your program.
Using instead of to reducing processing time Needs improvement More efficient data election; set elec94nc; if (district=1) or (district=3) or (district=4) or (district=7) or (district=8) or (district=12) then incumb = -1; Magazine get closer to its customers Providing modernisation programme for the Office of National Statistics From Our Blog SAS Viya Newsletter Sign up to receive email updates Terms & Conditions Additional help More on SAS Research Computing home page Last Updated: August 21, 2012 How can we improve this article? check over here These built-in functions and procedures use pre-compiled code that has been optimized.
To write efficient SAS programs, you will need to be aware of the resource limits of your computing environment. The “where” statement is also more efficient than the “if” statement since the “where” condition is met as the data are being read from the data set. IDRE Research Technology Group High Performance Computing Statistical Computing GIS and Visualization High Performance Computing GIS Statistical Computing Hoffman2 Cluster Mapshare Classes Hoffman2 Account Application Visualization Conferences Hoffman2 Usage Statistics 3D Of course, your program could be more complicated, but I wonder why you are mixing macro programming statements with DATA step variables.
Table 10. SAS also provides information on your data sets when you use “proc contents” or “proc datasets”. You can use either the label or the attrib statement to label variables. For example, if your data set is sorted by age, and you sort it by cat, the observations within each value of cat will, by default, still be sorted by age.
Use proc datasets to delete data sets you no longer need. Using one step to create multiple data sets Needs improvement More efficient data congelec; set allelec; if electype = "C"; run; data congrep; set allelec; if electype = "C" and party Develop and test in stages Debugging a program is easier if you test and debug individual components of the program separately.