Tips and Tricks for SAS Programmers. SUCCESS March 2018 Mary Harding

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1 Tips and Tricks for SAS Programmers SUCCESS March 2018 Mary Harding Copyright SAS Institute Inc. All rights reserved.

2 Agenda Tip 1 Sorting tip Tip 2 Don t read data over and over again :SASFILE Tip 3 Pattern Matching Tip 4 Substr (left side) 2

3 Agenda Tip 5 Create Native EXCEL files from ODS..It s FINALLY HERE! 3

4 Tip 1: Save on Sorting: Use the NOEQUALS Option PROC SORT : change default behavior Example: o First Sort 13 Cards Highest to lowest: o KK QQ JJ o Then sort by Suit. For observations with identical BYvariable values, EQUALS maintains the relative order of the observations within the input data set in the output data set. 4 Solution: Proc Sort, NOEQUALS option EQUALS is the default, and uses unnecessary CPU. If we look at the s, Proc Sort, maintains the relative order of the K Q J 5, even though we didn t need to.

5 Tip 1: Save on Sorting: Use the NOEQUALS Option First sort table by order_date. Now sort the same table by order_type Notice how SAS maintains the previous order_date order. 5

6 Tip 1: Save on Sorting: Use the NOEQUALS Option Use NOEQUALS option to save processing time. Proc Sort data=orders out=orders_ordertype Noequals; by Order_type; Run; PROC SORT DATA=prod.customers NOEQUALS ; I just care about the beer can size 6

7 Tip 2: Don t read data over and over again: SASFILE SASFILE Statement Loads TABLE keeps data in MEMORY Use when processing data across many steps Works if TABLE fits in Memory Remember to use SASFILE close statement to release memory Cannot write to file 7

8 Tip 2: Don t read data over and over again: SASFILE sasfile orion.customerdim load; Reduce processing proc freq data=orion.customerdim; SASFILE SAS-data-set LOAD; tables CustomerCountry CustomerType; run; proc print data=orion.customerdim noobs; where CustomerType='Orion Club Gold members high activity'; var CustomerID CustomerName CustomerAgeGroup; run; proc means data=orion.customerdim mean median max min; var CustomerAge; class CustomerGroup; run; proc tabulate data=orion.customerdim format=8.; class CustomerAgeGroup CustomerType; table CustomerType All=Total, CustomerAgeGroup*n=' ' All=Total*n=' '/rts=45; SASFILE SAS-data-set CLOSE; run; sasfile orion.customerdim close; 8

9 Tip 2: Don t read data over and over again: SASFILE Note: Cannot write to a table that is in-memory 9

10 Tip 3: Pattern Matching: PERL Regular Expressions (PRX) Open source language available in SAS Specifies Character patterns to search or replace Returns the Start position at which the pattern is found Returns 0 if pattern is not found Let s look at an example: I need to verify SIN Patterns 10

11 Tip 3: Pattern Matching : PERL Regular Expressions Data SIN; infile datalines dlm=","; input name:$30. sin:$20.; Datalines; Cary Grant, Humphrey Bogart, Lauren Bacall, Sophie Loren, jhu James Dean, HI Jerry Lewis, Catherine Hepburn, Cary Grant, LK8 Marlon Brando,Toronto Janet Lee,849-74N-e89 ; Run; 1. Verify Pattern: XXX-XXX-XXX 2. Verify that X is a digit 3. Verify there are no additional characters ap 7 Invalid SINs 11

12 Tip 3: Pattern Matching PERL Regular Expressions Data Invalid Good; set sin; If prxmatch('/\d{3}-\d{3}-\d{3}/',trim(sin))=0 then output Invalid /*did not find a pattern match*/; else output Good; Run; Metacharacter Role / Start or end regular expression \d{3} Match three digits - Dash between digits It almost works 12

13 Tip 3: Pattern Matching PERL Regular Expressions What happened to : James Dean, HI Marlon Brando,Toronto Hmm Why are these still considered VALID? The PRXMATCH is a sliding search so it did find XXX-XXX-XXX, We need to further qualify our search Toronto Force PRXMATCH to search for match ONLY from position 1 to 11, rather than search for the pattern anywhere in the string Metacharacter ^ Role Represents the beginning of the string, before the first character $ Represents the end of the string, after the last character 13

14 Tip 3: Pattern Matching PERL Regular Expressions Data Invalid Good; set sin; Run; ^ matches the position at the beginning of the input string if prxmatch('/^\d{3}-\d{3}-\d{3}$/',(sin))=0 then output Invalid; /*If equal to Zero, it did not find the pattern match and is INVALID*/ else output Good; It works $ matches the position at the end of the input string. 7 Invalid SINs, problem solved. 14

15 Tip 3: Perl Regular Expressions PRX can accomplish much more: Use in the DATA step to enhance search-andreplace text options. Use to perform the following tasks: o Validate data o Replace text o Extract a substring from a string 15

16 Tip 3: Pattern Matching: PRX vs VERIFY and LIKE functions Is there another way? o The VERIFY function has some similar properties to PERL Regular Expressions o Let s use the VERIFY function with the LIKE operator, to check SINs. 16

17 Tip 3: Pattern Matching: PRX vs VERIFY and LIKE functions Data Invalid_SIN; Set sin; Where SIN not Like ' - - ' or Verify(trim(compress(SIN,'-')),' ') ne 0; Run; VERIFY(target-expression, search expression, <search expression> ) Returns the position of the first character in target-expression that is not present in any search-expression. If there are no characters other than those in searchexpressions,verify returns a 0. Essentially a correct Pattern match. 17

18 Tip 3: Pattern Matching: PRX vs VERIFY and LIKE functions o An alternate solution that doesn t require learning Perl Regular expression syntax. o May not work for more complicated matching problems. 18

19 Tip 4: Substr(left side) You need to replace several characters in a string. Easy you say, I know several ways : o Tranwrd function o Translate o PRXCHANGE o Conditional logic Easy problem: Change values of the variable Pet. If Pet= Cat then change to Dog. Newpet=Tranwrd(Pet, Cat, Dog ); 19

20 Tip 4: Substr(left side) What if you have millions of characters that need to be changed, to a specific value. More difficult Problem: We need to Confidentialize credit card numbers. Any ideas Hint: it is a one line solution 20

21 Tip 4: Substr(left side) and Picture Format SUBSTR(variable, position <, length>)=characters to replace Replaces character values based on their position in a string, not their value. The one line solution.. Example SUBSTR(creditcard,13,4)= XXXX ; 21

22 Tip 4: Create native EXCEL- ODS EXCEL It s finally here, create native xlsx files from SAS Reports. Production SAS9.4 M3 (Experimental SAS9.4 M1 and M2) ODS EXCEL FILE="C:\Temp\colour_cells.xlsx" ; Proc report data=orion.emps(obs=20); column Name JobTitle Country Gender HireDate Salary; compute Name; count+1; if mod(count,2)=0 then call define(_row_,'style', 'style={background=lightgreen}'); endcomp; Run; ODS EXCEL CLOSE; 22

23 Tip 4: Create native EXCEL- ODS EXCEL 23

24 24 Copyr i g ht 2014, SAS Ins titut e Inc. All rights res er ve d. What to learn more Papers and Documentation o o o o o o Paper : Jolley, Linda T. Stroupe, Jane S. Dear Miss SASAnswers: A Guide to SAS Efficiency Paper : Virgile, Robert The Most Important Efficiency Techniques PERL Regular Expressions: ODS EXCEL Documentation: ault/viewer.htm#p09n5pw9ol0897n1qe04zeur27rv.htm 24

25 Questions? Copyright SAS Institute Inc. All rights reserved.

26 Thank You sas.com Copyright SAS Institute Inc. All rights reserved.