SAS 101 - sasCommunity_… · SAS® 101 Based on Learning SAS by Example: A Programmer‟s Guide...

SAS® 101

Based on

Learning SAS by Example:

A Programmer‟s Guide

Chapter 21, 22, & 23

By Tasha Chapman, Oregon Health Authority

Topics covered…

All the leftovers!

Infile options

Missover

LRECL=/Pad/Truncover

FirstObs=/OBS=

Topics covered…

Advanced formats and informats

User created informats

Reading both character and numeric data

Formats within formats

Saving formats

Using formats as look-up tables

CNTLIN and CNTLOUT datasets

Topics covered…

Transposing data

PROC Transpose

Other topics – Saving and storing macros

%Include

Autocall library

Stored compiled macros

Infile options

PROC Import with a twist (redux)

Run PROC Import

Copy the SAS log to the Program Editor

PROC Import will create a DATA step with INFILE and

INPUT statements in the log

Delete any non-SAS code

Modify informats, formats, and lengths (as needed)

Run the new code

From Week 3 – Chapters 5 & 6

PROC Import with a twist (redux)

Run PROC Import

Copy the SAS log to the Program Editor

Delete any non-SAS code

Modify informats, formats, and lengths (as needed)

Run the new code

Infile statement options


Common INFILE options

Option Purpose

dsd Stands for delimiter sensitive data. Changes default delimiter from blank to

comma. If two delimiters in a row, assumes missing value between. Quotes

stripped from character values.

dlm= Stands for delimiter. Specifies alternate delimiter(s).

missover At the end of an input line of raw data, sets remaining values to missing if there

are more variables than data values.

lrecl= Stands for logical record length. Specifies the record length of the raw data

file (necessary if greater than the default 256 bytes).

pad Pads the input records with blanks out the the end of the logical record length.

truncover Essentially has the effect of both PAD and MISSOVER options combined.

firstobs= Specifies which record number in the raw dataset is the first observation of

data. Useful if raw data includes headers.

obs= Specifies the record number of the last record to read. Useful if only want to

read a select number of observations.

http://www2.sas.com/proceedings/sugi26/p009-26.pdf

MISSOVER

Missing data results in

shorter than expected line

MISSOVER

MISSOVER option fills in the

blanks at the end of the line

with missing values.


Option Purpose
















FIRSTOBS=

FIRSTOBS=

First row contains header

information

FIRSTOBS=

FIRSTOBS=2 option starts

reading the raw data file

on the second row.


Option Purpose
















Advanced formats and informats

PROC Format (redux)

value $gender

Value statement begins new format

Can create more than one format per

PROC Format

$gender is the name of the new

format

Format name begins with a $ to

indicate that the format is to be

applied to Character data

Input

value

Output

value


What are informats? (redux)

Informats are instructions that tell SAS how to read

a data value

Can be as simple as w.d

3.1 tells SAS to read „123‟ as 12.3

$3. tells SAS to read „123‟ as „123‟ and store it as

character data

Excellent for reading dates, dollars, and percents

MMDDYY8. tells SAS to read ‟12/26/07‟ and store it

as 17526 (a SAS date that can be used for

calculations, etc.)


Creating informats

invalue score

Invalue statement creates informats

Dollar sign $ indicates format will

be creating character variables

(i.e. output value will be character)

Absence of dollar sign indicates

format will be creating numeric

variables (as in this example)

Input

value

Output

value

Creating informats

Survey scale entered as character values

(SA = Strongly Agree, A = Agree, etc.)

Want to convert to numeric Likert-type scale

Creating informats

Use PROC

Format to create

the informat

score

Apply the

informat while

reading in the

raw data

Creating informats

UPCASE option

Converts all input strings to uppercase before they are compared to ranges

JUST option

Left justifies all input strings before they are compared to ranges

Useful options as raw data may be messy (mixed case, leading blanks, etc.)

Creating informats

Dataset of patient temperature readings

Normal temperature coded as “N”

Actual temperature entered if not normal

Both character and

numeric data in

same field

Creating informats

Use PROC

Format to create

the informat

tempfmt

Numeric temperatures

within valid range will be

read as written.

“N” will be converted to

98.6.

Any other values

(including numeric temps

outside valid range) will

be converted to missing.


Formats and informats can be nested within each

other

Useful for applying multiple types of formats (e.g.

picture and value formats) to the same variable

depending on the data value


Phone directory dataset

Some provided full phone numbers

Want to show as (999) 999-9999

Some provided extensions

Want to show as x9999

Some have no phone number

Want to show as “Unlisted”


(503) 373-1793

x1793

Applies format based

on data value

Saving and storing formats

PROC Format saves user-created formats to a

catalog

Usually these catalogs are in the WORK library,

and are deleted at the end of each SAS Session

However, formats can be easily saved and stored to

other permanent libraries

http://support.sas.com/resources/papers/proceedings12/048-2012.pdf


Save a format to a permanent library using a

library= option

This will create a formats catalog

(called “formats” by default) in the

mylib folder



To use the saved formats in another program, use

the fmtsearch= option to add that catalog to the

list of available formats


CNTLIN/CNTLOUT

Can create a format from a dataset using the

CNTLIN= option in PROC Format

Can create a dataset from a format using the

CNTLOUT= option in PROC Format

CNTLIN/CNTLOUT

Have a dataset of ICD9

codes and descriptions

Want to convert this to a

SAS format

CNTLIN/CNTLOUT

The input dataset has to have specific variables:

FMTNAME – name of the format

START – the single value to be formatted (or start

value if the beginning of a range of values)

END (optional) – the end value of a range of values to

be formatted

LABEL – the formatted value

TYPE (optional) – type of format, C for character, N for

numeric

CNTLIN/CNTLOUT

Original dataset

Ready to be

made into a

format

CNTLIN/CNTLOUT

Use PROC Format to

convert the dataset

to a format

CNTLIN/CNTLOUT

Use PROC Format to

convert a format to a dataset

Transposing data

Transposing data

Transposing data

Transposing is converting variables to observations

and vice versa

Multiple ways of restructuring and transposing data

PROC Transpose

DATA step – Arrays and DO Loops

Transposing data – basic example

Input (original)

dataset

Two variables

Seven observations

Output (transposed) dataset

Seven variables

Two observations


data=

Input (original)

dataset

out=

Output (transposed)

dataset


Name of transposed variables

stored in “_NAME_” column


New variables generically

named COL1, COL2, etc.

VAR statement

The var statement specifies which variables should

be transposed

If omitted, by default PROC Transpose will only

transpose numeric variables

ID statement

The ID statement specifies which variables should

be used to name the new columns

If the value is not a valid variable name (e.g., starts

with a number), SAS will convert it to a valid name

(e.g., leading underscore)

ID statement

The variable names can be modified with the

prefix=, delimiter=, or suffix= options

Transposing data – BY groups

Two temperatures

(HighTemp and LowTemp)

Three cities

(Eugene, Portland, and Salem)

BY statement

Can specify more than one BY group variable

Data must be sorted by BY group variable(s)

City _NAME_ Day1 Day2 Day3 Day4 Day5 Day6 Day7

Eugene HighTemp 68 65 66 63 60 63 65

Eugene LowTemp 46 41 45 44 45 43 44

Portland HighTemp 62 63 61 62 60 62 66

Portland LowTemp 44 43 42 39 44 45 45

Salem HighTemp 65 66 62 60 58 62 68

Salem LowTemp 45 42 43 41 41 45 46

BY statement

DayOf Week City HighTemp LowTemp

1 Eugene 68 46

2 Eugene 65 41

3 Eugene 66 45

4 Eugene 63 44

5 Eugene 60 45

6 Eugene 63 43

7 Eugene 65 44

1 Portland 62 44

2 Portland 63 43

3 Portland 61 42

4 Portland 62 39

5 Portland 60 44

6 Portland 62 45

7 Portland 66 45

1 Salem 65 45

2 Salem 66 42

3 Salem 62 43

4 Salem 60 41

5 Salem 58 41

6 Salem 62 45

7 Salem 68 46

1 Portland 62 44

2 Portland 63 43

3 Portland 61 42

4 Portland 62 39

5 Portland 60 44

6 Portland 62 45

7 Portland 66 45

DayOf Week City HighTemp LowTemp

1 Eugene 68 46

2 Eugene 65 41

3 Eugene 66 45

4 Eugene 63 44

5 Eugene 60 45

6 Eugene 63 43

7 Eugene 65 44

1 Salem 65 45

2 Salem 66 42

3 Salem 62 43

4 Salem 60 41

5 Salem 58 41

6 Salem 62 45

7 Salem 68 46

NAME= option

Use the name= option to name the variable

containing the name of the transposed variable

(_NAME_ column)

Saving and storing macros


Need to store and share macro code

Multiple ways to save and store macros for future

use

%Include

Autocall facility

Stored compiled macro facility


Which method to choose depends on your needs

and operating environment

SAS recommends:

Don‟t store macros while still in development

If you are running production-level jobs using name-

style macros, consider stored compiled macros

If you are letting a group of users share macros,

consider the autocall facility

LIBNAME trick (redux)

Save your commonly used and/or passworded

LIBNAME statements in a text file (using Notepad)

Use a %include statement to reference the text file

at the beginning of every SAS program

SAS will include the code in

the text file as if it were

part of your program.


Save your macro definitions in a text file

Use %include to reference the file at the start of

every program

%Include

%Include

Advantages:

Easy and straightforward approach

Excellent first step towards starting a macro library

Disadvantages:

The macro definition is compiled every time the

%include is executed (inefficient)

If efficiency is an issue, each file should contain only

one macro (which would result in multiple files to

include)

Requires you to know where the physical text files are

stored

Autocall facility

An autocall library is a directory containing

individual files

Similar in concept to %include, but files stored as SAS

files

Each file contains one macro definition

The name of the file must be the same as the macro

name

An autocall library can also be a SAS catalog

Autocall facility

Save the SAS code for

your macro using the

macro name as the

program file name

To avoid confusion, this

folder should have nothing

but autocall macros

Autocall facility

To use the macro later…

Reference the folder storing the autocall macros with a FILEREF

(created with a filename statement)

Not a libref!

Autocall facility

mautosource option turns on the autocall macro facility

mautolocdisplay option (optional) displays the location of

the source code in the log when the macro is called

sasautos= option tells SAS where the autocall macros are

stored

Autocall facility

Advantages:

Macros stored as SAS code – can use enhanced editor

to modify them

User-defined macros stored in a standard location

No need to remember multiple file names when calling

macros

Macro code only compiled the first time it is used in a

session (efficient)

Easy to share

Autocall facility

Disadvantages:

Because macro code only compiled once per session,

this can be difficult during editing phase


Macros are always compiled before they are

executed

Compiled macros are stored in a catalog called

SASMACR

In a typical session, this catalog is stored in the

WORK library

However, this catalog can be stored in a more

permanent library for future use


Create a library to store the SASMACR catalog


mstored option turns the stored compiled macro facility on

sasmstore= option identifies the library

where the SASMACR catalog will be stored


Run the macro you want to store

store option tells SAS to store this macro

source option (optional) stores the source code with the

compiled code

des= option (optional) assigns a descriptive title for the macro

entry in the SAS catalog


To use the macro later…

mstored option turns the stored compiled macro facility on

sasmstore= option identifies the library

where the SASMACR catalog is stored


SASMACR catalog

available to view in the

Explorer Window

Description stored as a file property

(Right-click Properties)


If the source option was used during

macro storage, the source code can be

retrieved using %copy

(Code will be printed to log)


Advantages:

Macro programs only compiled once

Compile and store is faster

Can store more than one macro per catalog

Keeping track of macros is easy

Source code does not have to be stored with SASMACR

catalog

But for maintenance purposes, it is recommended


Disadvantages:

Cannot recreate source statements from a compiled

macro

Cannot be moved directly to other operating systems

Must be saved and recompiled under new OS at any

new location

May need to be recompiled for new releases of SAS


If macros are stored in multiple locations, SAS will

search for macro definitions in this order:

WORK.SASMACR catalog


Autocall macros

Additional Reading

Missover, Truncover, and Pad, Oh My!! or Making Sense of the Infile and Input Statements

Yes We Can…Save SAS Formats

Learn the Basics of Proc Transpose

Turning the Data Around: Proc Transpose and Alternative Approaches

Use of a Macro to Revise Data

Creating a Stored Macro Facility in Ten Minutes

Ways to Store Macro Source Codes and How to Retrieve Them

Building and Using Macro Libraries








http://www2.sas.com/proceedings/forum2007/046-2007.pdf

http://www.sascommunity.org/wiki/Use_of_a_macro_to_revise_data

http://www2.sas.com/proceedings/forum2008/101-2008.pdf

http://analytics.ncsu.edu/sesug/2005/AD07_05.PDF


That‟s all, folks!

You Did It!

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