SAS(R) 9.2 Language Reference: Concepts
SAS System Concepts- Essential Concepts of Base SAS Software
- What Is SAS?
- Overview of Base SAS Software
- Components of the SAS Language
- Ways to Run Your SAS Session
- Customizing Your SAS Session
- Conceptual Information about Base SAS Software
- SAS Processing
- Rules for Words and Names in the SAS Language
- SAS Variables
- Definition of SAS Variables
- SAS Variable Attributes
- Ways to Create Variables
- Variable Type Conversions
- Aligning Variable Values
- Automatic Variables
- SAS Variable Lists
- Dropping, Keeping, and Renaming Variables
- Numeric Precision in SAS Software
- Missing Values
- Definition of Missing Values
- Creating Special Missing Values
- Order of Missing Values
- When Variable Values Are Automatically Set to Missing by SAS
- When Missing Values Are Generated by SAS
- Working with Missing Values
- Expressions
- Definitions for SAS Expressions
- Examples of SAS Expressions
- SAS Constants in Expressions
- SAS Variables in Expressions
- SAS Functions in Expressions
- SAS Operators in Expressions
- Dates, Times, and Intervals
- Error Processing and Debugging
- SAS Output
- Definitions for SAS Output
- Routing SAS Output
- The SAS Log
- Traditional SAS Listing Output
- Changing the Destination of the Log and the Output
- Output Delivery System
- BY-Group Processing in SAS Programs
- WHERE-Expression Processing
- Definition of WHERE-Expression Processing
- Where to Use a WHERE Expression
- Syntax of WHERE Expression
- Combining Expressions by Using Logical Operators
- Improving Performance of WHERE Processing
- Processing a Segment of Data That Is Conditionally Selected
- Deciding Whether to Use a WHERE Expression or a Subsetting IF Statement
- Optimizing System Performance
- Definitions for Optimizing System Performance
- Collecting and Interpreting Performance Statistics
- Techniques for Optimizing I/O
- Techniques for Optimizing Memory Usage
- Techniques for Optimizing CPU Performance
- Calculating Data Set Size
- Support for Parallel Processing
- Monitoring Performance Using Application Response Measurement (ARM)
- The SAS Registry
- Printing with SAS
- Universal Printing
- Managing Printing Tasks with the Universal Printing User Interface
- Configuring Universal Printing with Programming Statements
- Forms Printing
- Using TrueType Fonts with Universal Printers and SAS/GRAPH Devices in SAS 9.2
- Creating Scalable Vector Graphics Using Universal Printing
- Creating Portable Network Graphics Using Universal Printing
- Windowing Environment Concepts
- Introduction to the SAS Windowing Environment
- What Is the SAS Windowing Environment?
- Main Windows in the SAS Windowing Environment
- Navigating in the SAS Windowing Environment
- Getting Help in SAS
- List of SAS Windows and Window Commands
- Managing Your Data in the SAS Windowing Environment
- DATA Step Concepts
- DATA Step Processing
- Why Use a DATA Step?
- Overview of DATA Step Processing
- Processing a DATA Step: A Walkthrough
- About DATA Step Execution
- About Creating a SAS Data Set with a DATA Step
- Writing a Report with a DATA Step
- The DATA Step and ODS
- Reading Raw Data
- Definition of Reading Raw Data
- Ways to Read Raw Data
- Types of Data
- Sources of Raw Data
- Reading Raw Data with the INPUT Statement
- How SAS Handles Invalid Data
- Reading Missing Values in Raw Data
- Reading Binary Data
- Reading Column-Binary Data
- BY-Group Processing in the DATA Step
- Definitions for BY-Group Processing
- Syntax for BY-Group Processing
- Understanding BY Groups
- Invoking BY-Group Processing
- Determining Whether the Data Requires Preprocessing for BY-Group Processing
- Preprocessing Input Data for BY-Group Processing
- How the DATA Step Identifies BY Groups
- Processing BY-Groups in the DATA Step
- Reading, Combining, and Modifying SAS Data Sets
- Definitions for Reading, Combining, and Modifying SAS Data Sets
- Overview of Tools
- Reading SAS Data Sets
- Combining SAS Data Sets: Basic Concepts
- Combining SAS Data Sets: Methods
- Error Checking When Using Indexes to Randomly Access or Update Data
- Using DATA Step Component Objects
- Introduction to DATA Step Component Objects
- Using the Hash Object
- Using the Hash Iterator Object
- Using the Java Object
- Array Processing
- SAS Files Concepts
- SAS Libraries
- Definition of a SAS Library
- Library Engines
- Library Names
- Library Concatenation
- Permanent and Temporary Libraries
- SAS System Libraries
- Sequential Data Libraries
- Tools for Managing Libraries
- SAS Data Sets
- Definition of a SAS Data Set
- Descriptor Information for a SAS Data Set
- Data Set Names
- Data Set Lists
- Special SAS Data Sets
- Sorted Data Sets
- Tools for Managing Data Sets
- Viewing and Editing SAS Data Sets
- SAS Data Files
- Definition of a SAS Data File
- Differences between Data Files and SAS Views
- Understanding an Audit Trail
- Understanding Generation Data Sets
- Understanding Integrity Constraints
- Understanding SAS Indexes
- Compressing Data Files
- SAS Views
- Definition of SAS Views
- Benefits of Using SAS Views
- When to Use SAS Views
- DATA Step Views
- PROC SQL Views
- Comparing DATA Step and PROC SQL Views
- SAS/ACCESS Views
- Stored Compiled DATA Step Programs
- Definition of a Stored Compiled DATA Step Program
- Uses for Stored Compiled DATA Step Programs
- Restrictions and Requirements for Stored Compiled DATA Step Programs
- How SAS Processes Stored Compiled DATA Step Programs
- Creating a Stored Compiled DATA Step Program
- Executing a Stored Compiled DATA Step Program
- Differences between Stored Compiled DATA Step Programs and DATA Step Views
- Examples of DATA Step Programs
- DICTIONARY Tables
- SAS Catalogs
- Definition of a SAS Catalog
- SAS Catalog Names
- Tools for Managing SAS Catalogs
- Profile Catalog
- Catalog Concatenation
- About SAS/ACCESS Software
- Definition of SAS/ACCESS Software
- Dynamic LIBNAME Engine
- SQL Procedure Pass-Through Facility
- ACCESS Procedure and Interface View Engine
- DBLOAD Procedure
- Interface DATA Step Engine
- Processing Data Using Cross-Environment Data Access (CEDA)
- Definition of Cross-Environment Data Access (CEDA)
- Advantages of CEDA
- SAS File Processing with CEDA
- Alternatives to Using CEDA
- Creating Files in a Foreign Data Representation
- Examples of Using CEDA
- SAS 9.2 Compatibility with SAS Files from Earlier Releases
- Introduction to Version Compatibility
- Comparing SAS System 9 to Earlier Releases
- Using SAS Library Engines
- File Protection
- Definition of a Password
- Assigning Passwords
- Removing or Changing Passwords
- Using Password-Protected SAS Files in DATA and PROC Steps
- How SAS Handles Incorrect Passwords
- Assigning Complete Protection with the PW= Data Set Option
- Encoded Passwords
- Using Passwords with Views
- SAS Data File Encryption
- SAS Engines
- Definition of a SAS Engine
- Specifying an Engine
- How Engines Work with SAS Files
- Engine Characteristics
- About Library Engines
- Special-Purpose Engines
- SAS File Management
- Improving Performance of SAS Applications
- Moving SAS Files between Operating Environments
- Repairing Damaged SAS Files
- External Files
- Industry Protocols Used in SAS
- The SMTP E-Mail Interface
- Sending E-Mail through SMTP
- System Options That Control SMTP E-Mail
- Statements That Control SMTP E-mail
- Universal Unique Identifiers
- IPv6
- Appendix
Index here
| Product | Release |
|---|---|
| Base SAS | 9.2 |
- Type
- Usage and Reference
- Copyright Date
- February 2009
- Last Updated
- 30Sep2009
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| Previous Page | | | Next Page |
| Missing Values |
Definition of Missing Values
- missing value
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is a value that indicates that no data value is stored for the variable in the current observation. There are three kinds of missing values:
By default, SAS prints a missing numeric value as a single period (.) and a missing character value as a blank space. See Creating Special Missing Values for more information about special numeric missing values.
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Copyright © 2009 by SAS Institute Inc., Cary, NC, USA. All rights reserved.
