tips and tricks for sas programmers group...title chapter 4: creating simple queries author susan...

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Tips and Tricks for SAS Programmers

SUCCESSMarch 2018Mary Harding

2

Copyr i g ht © 2014, SAS Ins t i tu t e Inc . A l l r ights reser ve d .

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)

3


Agenda

Tip 5 Create Native EXCEL files from

ODS…..It’s FINALLY HERE !

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 10 9 8 7 6 5 3

o Then sort by Suit.

Solution: Proc Sort, NOEQUALS option

For observations with identical BY-

variable values, EQUALS maintains

the relative order of the

observations within the input data

set in the output data set.

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.

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First sort table by

order_date.

• Now sort the same table by

order_type

• Notice how SAS maintains

the previous order_date

order.


6


PROC SORT DATA=prod.customers NOEQUALS ;

I just care about the beer

can size


Proc Sort data=orders out=Orders_ordertype Noequals;

by Order_type;

Run;

Use NOEQUALS option to save processing time.

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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

Tip 2: Don’t read data over and over again: SASFILE

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sasfile orion.customerdim load;

proc freq data=orion.customerdim;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;run;sasfile orion.customerdim close;


SASFILE SAS-data-set LOAD;

SASFILE SAS-data-set CLOSE;

Reduce

processing

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Note: Cannot write to a table that is in-memory

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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

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Tip 3: Pattern Matching : PERL Regular Expressions

Data SIN;

infile datalines dlm=",";

input name:$30. sin:$20.;

Datalines;

Cary Grant,345-667-888

Humphrey Bogart,56-444-890

Lauren Bacall, 458-897-987

Sophie Loren, jhu-987-90

James Dean,789-378-123HI

Jerry Lewis,987-99-089

Catherine Hepburn,883-268-169

Cary Grant,564-878-LK8

Marlon Brando,Toronto234-582-873

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

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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

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What happened to :

James Dean,789-378-123HI

Marlon Brando,Toronto234-582-873

The PRXMATCH is a sliding search so it did find XXX-XXX-XXX, We need to further qualify our search Toronto234-582-873

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

Hmm…Why are these

still considered VALID?

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Data Invalid Good;

set sin;

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;

Run;

It works

^ matches the position at the

beginning of the input string

$ matches the position at the

end of the input string.

7 Invalid SINs, problem

solved.

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Tip 3: Perl Regular Expressions

PRX can accomplish much more:

Use in the DATA step to enhance search-and-

replace text options.

Use to perform the following tasks:

o Validate data

oReplace text

o Extract a substring from a string

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Tip 3: Pattern Matching: PRX vs VERIFY and LIKE functions

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.

Is there

another

way?

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Data Invalid_SIN;

Set sin;

Where SIN not Like '___-___-___' or

Verify(trim(compress(SIN,'-')),'0123456789') 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 search-

expressions,VERIFY returns a 0. Essentially a correct Pattern match.

http://127.0.0.1:64378/help/ds2ref.hlp/n1seyho5bsm4tpn1iqdzu4gqzfju.htm#n1p1wn0hk1h6bjn1qgdfmdbjskxq

http://127.0.0.1:64378/help/ds2ref.hlp/n1seyho5bsm4tpn1iqdzu4gqzfju.htm#p19n8nixbfh7u6n1dr96so3cju8m

http://127.0.0.1:64378/help/ds2ref.hlp/n1seyho5bsm4tpn1iqdzu4gqzfju.htm#p19n8nixbfh7u6n1dr96so3cju8m

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o An alternate solution that doesn’t require

learning Perl Regular expression syntax.

o May not work for more complicated

matching problems.

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’);

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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

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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’;

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▪ 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;

Tip 4: Create native EXCEL- ODS EXCEL

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Tip 4: Create native EXCEL- ODS EXCEL

24


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What to learn more Papers and Documentation

o Paper 042-2007: Jolley, Linda T. Stroupe, Jane S. Dear Miss

SASAnswers: A Guide to SAS® Efficiency

o Paper 209-2007: Virgile, Robert The Most Important Efficiency

Techniques

o PERL Regular Expressions:

http://www2.sas.com/proceedings/forum2007/223-2007.pdf

o http://support.sas.com/rnd/base/datastep/perl_regexp/regexp-tip-

sheet.pdf

o ODS EXCEL Documentation:

http://support.sas.com/documentation/cdl/en/odsug/67921/HTML/def

ault/viewer.htm#p09n5pw9ol0897n1qe04zeur27rv.htm

o https://blogs.sas.com/content/sgf/2017/02/20/tips-for-using-the-ods-

excel-destination/






http://support.sas.com/rnd/base/datastep/perl_regexp/regexp-tip-sheet.pdf

http://support.sas.com/documentation/cdl/en/odsug/67921/HTML/default/viewer.htm#p09n5pw9ol0897n1qe04zeur27rv.htm

https://blogs.sas.com/content/sgf/2017/02/20/tips-for-using-the-ods-excel-destination/


Questions?

sas.com


Thank You___________________________

[email protected]

http://www.sas.com/

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