Creating and Using Custom Formats for
Data Manipulation and Summarization
Presentation to
Denver SAS Users Group
January 14, 2009
Presented by
John Schmitz, Ph.D.
Schmitz Analytic Solutions, LLC
Certified Advanced Programmer for SAS ®9
Summary
• Summary:
• This presentation will review creation of custom formats
directly in PROC FORMAT as well as through the data
step.
• These formats will then be used as lookup tables in a data
step, replacing a merge and for summarization within a
CLASS statement.
• Audience:
• The presentation is introductory to intermediate level. No
experience with SAS formats is assumed.
• This talk will serve as a base for our second talk on
Multilabel formats.
Schmitz Analytic Solutions, 2009
Outline
•
•
•
•
•
Define meaning of a ‘SAS Custom Format’
Creating custom formats with PROC FORMAT.
Creating custom formats in a DATA STEP.
Using a custom format within a CLASS statement.
Using a custom format in place of a data merge.
Schmitz Analytic Solutions, 2009
Before I Begin
• Nikki Carroll presented ‘Tap Into the Power of Formats’ (JUL
07). That presentation is available on www.denversug.org. It
will provide a nice complement to the comments I have here.
Schmitz Analytic Solutions, 2009
A Quick note on Naming Convention
• Throughout today’s presentations, you will notice a naming
convention.
• Format names end in Fmt
• Informat names end in InFmt
• Multilabel formats end in MLF
• When data sets are used, dataset names match the name
of the format they define.
• This is my naming convention and is not required to make the
code work.
Schmitz Analytic Solutions, 2009
Defining a ‘SAS Custom Format’
• SAS has many built in formats that most users already use:
(6.2, DOLLAR8.2, YYQ6., COMMA15.0, $15., DATE9.)
• Base SAS provides PROC FORMAT which allows the user to expand
the pre-defined format list with formats tailored to specific needs.
These are ‘SAS Custom Formats’.
• PROC FORMAT allows creation of a
• FORMAT (numeric or character)
• INFORMAT (numeric or character)
• PICTURE (numeric)
• Custom formats are stored in catalogs.
• by default in work.formats and cleared at end of session.
• User can define an alternate catalog and retain formats.
Schmitz Analytic Solutions, 2009
Creating a simple custom format
PROC FORMAT;
value $BossNamefmt
‘1’ = ‘Abe Lincoln’
‘2’ = ‘George Washington’ ;
RUN;
DATA example1;
SET sashelp.company;
boss = PUT(DeptHead,$BossNameFmt20.);
RUN;
Input field is $15 format
so a character format is
required.
Use format width to
define length of output
character variable.
For a PUT, match VARIABLE and FORMAT types,
output will be CHAR.
Use FORMAT with PUT and use
INFORMAT with INPUT.
Schmitz Analytic Solutions, 2009
For a INPUT, use CHAR variable, output type
will match format type.
See SAS Example1.
A quick INFORMAT Case
PROC FORMAT;
invalue $GroupInFmt
'FINANCE'
= 'FIN'
‘MARKETING' = 'M/S'
'SALES'
= 'M/S'
'MIS'
= 'MIS'
other
= 'N/A’;
invalue CityInFmt
'LONDON'
= 1
'NEW YORK' = 2
'TOKYO'
= 3;
RUN;
This format is a great example of
how custom formats could be used
to replace a large SELECT statement
within code.
Keyword OTHER is used for any
unspecified value.
Output variables are same type as
the informat used.
DATA example2;
set sashelp.company (keep=level2 level4);
GroupCode = input(LEVEL4,$GroupInFmt.);
CityID = input(LEVEL2,CityInFmt.);
RUN;
Schmitz Analytic Solutions, 2009
See SAS Example2.
A more realistic format example
PROC FORMAT;
value seasonsFmt
other
low
‘21DEC2008’d
’20MAR2009’d
’21JUN2009’d
’22SEP2009’d
’21DEC2009’d
RUN;
-
<
<
<
<
<
Special values LOW and
HIGH can be used for MIN
and MAX values.
Schmitz Analytic Solutions, 2009
‘21DEC2008’d
’20MAR2009’d
’21JUN2009’d
’22SEP2009’d
’21DEC2009’d
high
=
=
=
=
=
=
=
‘Missing’
‘Prior ’
‘2009S1’
‘2009S2’
‘2009S3’
‘2009S4’
‘Post
’;
-< START is INCLUSIVE. END is EXCLUSIVE
<- START is EXCLUSIVE. END is INCLUSIVE
<-< NEITHER VALUE IS INCLUSIVE
- BOTH VALUES ARE INCLUSIVE
Creating custom formats in a DATA STEP.
• The PROC FORMAT examples shown have many limitations.
• More complex cases can become very lengthy.
• Content is not dynamic.
• Code can be difficult to maintain.
• May wish to ‘auto generate’ code from data set contents
from programming logic.
• DATA STEPS can be used to greatly expand the usability of
custom formats.
Schmitz Analytic Solutions, 2009
PROC FORMAT IMPORT / EXPORT FEATURE
• PROC FORMAT provides options to read (write) format definitions
from (to) data sets.
• To generate a data set containing data from custom formats:
PROC FORMAT cntlout = formats;
RUN;
• To generate a (or multiple) custom format from data set:
PROC FORMAT cntlin = formatData;
RUN;
This data file must contain variables: START FMTNAME and LABEL.
Other fields can be included to further control the format definition.
Schmitz Analytic Solutions, 2009
Equinox data
Data stored in EquinoxData.xls
Season
Begins
Ends
1988S1
22-Dec-87
20-Mar-88
1988S2
20-Mar-88
21-Jun-88
1988S3
21-Jun-88
22-Sep-88
1988S4
22-Sep-88
21-Dec-88
1989S1
21-Dec-88
20-Mar-89
1989S2
20-Mar-89
21-Jun-89
…
2010S4
Schmitz Analytic Solutions, 2009
…
23-Sep-10
…
21-Dec-10
Converting RAW DATA to FORMAT
data SeasonsFmt;
set equinoxData (rename=(begins=START ends=END season=LABEL))
end=last;
length HLO $5;
retain fmtname 'SeasonsFmt' SEXCL 'N' EEXCL 'Y' hlo '‘
firstDate ;
if _N_ = 1 then firstDate = start;
output;
if last then do;
start = end; end=.; label = 'POST'; hlo = 'H';EEXCL=‘N’;
output; EEXCL=‘Y’;
hlo=‘O'; start=.; end=.; label='MISSING';
output;
start = .; end= FirstDate; label = 'PRIOR'; hlo = 'L';
output;
end;
keep start end label fmtname hlo sexcl eexcl;
format start end date9.;
run;
Schmitz Analytic Solutions, 2009
Using the Custom Format in PROC MEANS
DATA sample;
set sashelp.citiday
(keep=date SNYDJCM);
RUN;
PROC MEANS data=sample N MEAN;
class DATE;
format DATE seasonsFmt.;
var SNYDJCM;
RUN;
Schmitz Analytic Solutions, 2009
See SAS Example3.
Using custom formats as a convenient lookup table.
• Custom formats can be used for lookup tables, potentially
avoiding complex table joins and resource intensive sorts.
• These lookup tables are limited to one field as a lookup criteria.
*
• Use of lookup formats will require additional memory since the
format definition is maintained in memory.
• They perform best when the lookup table is small relative to
the main table.
* One can use HASH tables for lookups involving multiple
criteria and obtain similar performance benefits.
Schmitz Analytic Solutions, 2009
COMMENTS / QUESTIONS?
For More Information, Contact
John Schmitz
Schmitz Analytic Solutions
Phone: 303-482-1860
Email: Jschmitz@SchmitzAnalytics.com
Web: http://www.SchmitzAnalyticSolutions.com
Schmitz Analytic Solutions, 2009