1. Chapter 1: Introduction to SAS
SAS programs: A sequence of statements in a particular order
Rules for SAS statements:
Every SAS statement ends in a semicolon
Upper/lower case does not matter in SAS
© Fall 2011 John Grego and the University of South Carolina

2. SAS Statements Rules for SAS statements:
Statements can continue on next line
Statements can be on same line as other statements
Statements can start in any column
© Fall 2011 John Grego and the University of South Carolina

3. SAS Comments Rules for SAS comments: Comment “boxes” are popular
Comments: Two possible styles
*….; or /*….*/
*Here is a comment;
/* Here is another comment */
/* could be a control symbol in older languages.
© Fall 2011 John Grego and the University of South Carolina

4. SAS Data Sets
Specially formatted “worksheet”; current extension is .sas7bdat
Variables represented by Columns
32,767 variables or more
Observations represented by Rows
Two Data Types; Numeric and Character
Default variable length is 8
Run agency.sas Go to WORK.agency and look at worksheet. Two data types, but many data formats (show in Column Attributes).

5. SAS Variables Choose data type based on how you use the variable
Example: SSN could be character
Missing data in SAS is denoted by a period (.) for numeric data and a null space for character data
Variable attributes (Type, Length, etc) are stored with the SAS data set

6. Rules for Naming SAS variables
Names can be 32 characters or fewer
Names must begin with a letter or underscore (_)
Names may contain only letters, numbers, and underscores
Names can contain upper/lower case letters
I keep variable names short.

7. Two Parts to SAS Programs: Data Step
When ads ask for “SAS experience”, they mean experience with the DATA step
Begins with DATA statements
Reads in and modifies data
Creates SAS data set
Employers are interested in data management skills

8. Two Parts to SAS Programs: PROC Step
Begins with PROC statements
Performs (statistical) analyses on data
Produces results/outputs

9. Steps and Statements Steps may contain many statements
Steps usually end when:
Another step begins
A RUN; statement appears
DATA height; ..SAS statements.. run; PROC PRINT DATA=height; PROC REG;
Another step (DATA or PROC). There are several less common ways to end a step (quit, etc)

10. Implicit Looping
SAS reads data sets one observation at a time-implicit looping
SAS executes steps line by line
Be sure to enter statements in correct order
Order is fungible in SAS data steps (though text indicates otherwise).

11. Windowing Environment
PCs in labs and classrooms use windowing environment.
See Sec for information on other SAS environments
SAS OnDemand uses Studio, not Display Manager. Enterprise Guide has a project-based windowing environment.

12. SAS Windows: Right Frame
3 windows in one frame and 2 windows in another
“Editor”: Type in and edit SAS programs in the editor window (color-coded)
“Log”: Contains notes about SAS code execution, SAS data sets, and errors/warnings
“Results Viewer”: Printable results
Other named SAS programs also appear. Results Viewer has supplanted Output.

13. SAS Windows: Left Frame
3 windows in one frame and 2 windows in another
“Results”: Table of contents for Results Viewer window
“Explorer”: Icons for file folders, SAS libraries, and SAS data sets
Additional output windows (Output, Graphics)
I don’t use Results as much as I should. SPSSX has this output layout too. Run agency.sas (if you haven’t already).

14. Running Programs
Once program is entered into “Editor”, save it, then choose “Submit” under “Run” menu (Or “make the little man run”)
Go to Output and Log windows for results or notes
If program disappears, choose “Recall Last Submit” under “Run” menu

15. Log Window
In any window: Choose “Edit”->”Clear All” by right-clicking to clear window (Output and Log windows can get cluttered)
Log window -> Error messages, number of observations and variables created. Often hard to interpret, but info on intermediate datasets can be helpful
Open in New Window does not open individual objects…

16. Results Viewer Window Printing/Saving Output:
Directly from Results Viewer window (cut-and-paste to file (Word or Notepad); edit and print;
Using Results window (format options are limited)

17. Output Window Creating Output window:
Tools->Options->Preferences->Results
Click “Create Listing”
Both styles of output will be available

18. SAS Libraries Location where SAS data sets and SAS files are stored
Often, an ordinary directory that contains non-SAS files as well
Built-in libraries: Sashelp, Sasuser, Work (default library)
Sashelp has stored datasets

19. Creating SAS Libraries
Creating Libraries:
In active Libraries windows, select File->New, or right click and select New
Use method in Section 1.11, or select the sparkly file cabinet drawer
Name:
Libref (8 characters or fewer)
Path (location for data sets to be stored)
Enable at start-up

20. SAS Library Locations
Library location can easily be forgotten (if not enabled)
SAS prompts you to save in a separate file the code that created the library
It’s convenient to include simple code at the top of your file:
libname mitchell ‘z:\stat 540\Mitchell’;

21. Over-writing a Permanent Data Set
Be careful that you do not write over a saved file:
/* This code stores a data set from WORK in MITCHELL */
/* It can also accidentally overwrite any changes in mitchell.anpp in subsequent runs */
libname mitchell ‘z:\stat 540\mitchell’;
data mitchell.ANPP; set ANPP;
Mitchell.anpp may be a base data set for many subsequent data steps, so this write-over is severe.

22. Viewing Data Sets in Explorer
Double-click on a library, then double-click on an available dat a set (e.g, “Class” in Sashelp) or right-click and select Properties.
Close window when finished examining data set
Examine data set worksheet for problems
Right-click on column label and select “Column attributes” to obtain info on the variable in the data set.

23. SAS System Options
OPTIONS statement can appear before the DATA statement
Frequently used to improve pagination and on-screen readabililty of output
OPTIONS LINESIZE=80 NOCENTER NODATE PAGESIZE=64 NONUMBER;