Introduction to SAS for Windows

Topics

• Tutorial:
• External files
  • Data files
  • SAS program files
  • Using an external editor
  • Reading SPSS files

1. Tutorial:

1. Logon to Hebb network.. As usual, login to the network. [If you have not yet gotten your userid, work with another student.]
2. Start SAS. From the desktop, double-click the SAS V9 icon .
3. Windows: The SAS Window system is referred to as the "SAS Display Manager", which is largely the same on all systems. Initally, there are four main SAS windows, plus a bunch of others you can use.
   • Explorer: With panes for Explorer (SAS libraries, file shortcuts), and Results. Once you have some output, the Results pane shows a tree-like summary of your Output Window. From the Results pane you can select, delete or edit the procedure output before printing or saving your results.
   • Log: Your session LOG. Notes and Error messages appear here.
   • Program Editor: Enter and edit SAS program lines.
   • Output: Output from SAS procedures. Initially hidden behind the Log and Program Editor windows, this window pops to the foreground when program output is produced.
   Other windows:
   • Help -The Help facility contains SAS syntax descriptions for almost all of the SAS system (PROCs, DATA step statements, etc.) Note that the Help button on the toolbar is more useful for documentation than the Help menu.
   • Graph - High-resolution graphs appear in their own window. You can print or save them (one at a time).
4. Keyboard. Become familiar with the locations of special keys on the keyboard. Most of the standard Windows shortcut keys work as expected (e.g., Ctrl-X, Ctrl-C, Ctrl-V for Cut, Copy, Paste). See the SAS Control and Function Keys sheet. Use Ctrl-E to clear the contents of any window. Also, F9 ('keys') pops up the Keys window with the SAS key definitions. Here is a list of handy special keys:

   Home              Move to beginning of line
   End               Move to end of line
   PgDn              Move down one screen
   PgUp              Move up one screen
   Ctrl <-           Move left one word
   Ctrl ->           Move right one word
   Home              Move to beginning of line
   End               Move to end of line
   
   Ctrl-C            Copy selected text to clipboard
   Ctrl-X            Cut selected text to clipboard
   Ctrl-V            Paste from clipboard
   
   Ctrl-E            Clear window
   Ctrl-Z            Undo last action
     
   F1                Help
   F3                Submit
   F9                Show Keys window, with definitions of special keys
   

5. Menus: Like other Windows apps, SAS has the standard pull-down menus (File, Options, Windows, Help) at the top of the main SAS window.

   There is also a Menu item available by clicking in the upper left corner of the Editor, Log, or Output window and a popup menu with the same choices available by clicking the Right mouse button in these windows.

6. Entering program steps in the Editor window. In interactive SAS, you can submit program steps from the Editor as soon as you have typed in one or more complete DATA or PROC step. SAS runs each step as soon as it knows that it is complete: when it sees (a) a new DATA step, (b) a new PROC step, or (c) a run; statement.
   • Enter the small program below. Note how words are colored as you type.

     title 'Class data set';
     data class;
        input name $ sex $ age height weight;
     datalines;
     Alfred    M 14 69.0 112.5
     Alice     F 13 56.5  84.0
     Barbara   F 13 65.3  98.0
     Carol     F 14 62.8 102.5
     Henry     M 14 63.5 102.5
     James     M 12 57.3  83.0
     Jane      F 12 59.8  84.5
     Janet     F 15 62.5 112.5
     Jeffrey   M 13 62.5  84.0
     John      M 12 59.0  99.5
     Joyce     F 11 51.3  50.5
     Judy      F 14 64.3  90.0
     ;
     run;
     

   • Submit the DATA step: Raise the Program Editor menu (Right mouse button) and select Run -> Submit , or press F3, or click the Submit button in the Tool Bar.
   • Add a PROC step or two:

     proc corr data=class;
     run;
     proc reg data=class;
        model weight = height;
     run;
     

     Submit (or F3) again. Note that each PROC or DATA step is not executed until you type run; or submit another DATA or PROC statement.
   • Editing program lines: You can edit the lines in the Program Editor simply by overtyping. There are a variety of editing commands available. If you select a set of lines with the mouse, and click the submit button, only those lines are submitted.

   Modify the PROC REG step to ask for a display of predicted values and residuals, and a plot of residual vs. predicted. There are many options you can use with most SAS procedures.

   proc reg data=class;
      model weight = height / p;
      plot residual. * predicted.;
   run;
   
   
   
   Printing & Saving your results: The currently
   selected window (Editor, Log, Output) can be saved or printed from
   the File menu. Each window must be saved or printed
   separately. 
   
   
   Select File -> Print to print the current
   window.
   
   Select File -> Save As [if you have not yet
   named your file] or File -> Save [if your file has
   been named]. The default location is your home directory, named
   with your userid, the F:\ drive.
   
   
   For this tutorial, 
   
   
   Save the SAS statements from the Program Editor window. Type
   Tut1 in the File name: box. The statements will be
   saved as Tut1.sas.
   
   Save the output from the Output window. Type Tut1
   in the File name: box. The statements will be saved as
   Tut1.lst.
   
   
   
   Loading class data. Your instructor may have SAS data
   files which are stored on the server. To use one, e.g., the Baseball 
   data, type: 
   
   %include data(baseball);
   
   
   You may then proceed to do analyses with this dataset, e.g., for a
   univariate display, type: 
   
   proc univariate plot data=baseball;
      var salary;
      histogram salary / normal;
      run;
   
   
   
   Running class examples. Your instructor may have created
   examples or SAS data files which are stored on the server. To use
   one, 
   
   
   select Open from the File menu.
   
   On the Open panel, select Drive N:, then the directory for your
   course. e.g., n:\psy3030\examples\regress.
   
   Select a file in the File panel (e.g., therapy.sas),
   then click OK. The selected file should appear in the Program
   Editor window.
   
   
   

Getting help

SAS Analyst

1. Open the Nations data set in the Analyst application from the work library.
2. Explore the new Statistics menu which appears. Try Descriptive --> Distributions... for univariate summaries (the same as proc univariate gives)
3. Explore the new Graphs menu. Try a Histogram of one variable, or a Scatterplot of two variables.
   

Data transformations with SAS Analyst

Once you have switched to Edit mode, you can calculate a new variable. To calculate the log of Infant Mortality Rate, for example, use the Compute option in the Transform submenu of the Data menu. The panel that appears contains all SAS functions, classified in various categories (log is in the Mathematical category).
More detailed instructions and examples are contained in the document, SAS for Windows and the Analyst Application from the University of Texas.

2. External files

Using the Import Wizard

The Import Wizard is a convenient tool for reading in data stored in file formats other than the SAS dataset format. Simply go to the File menu and select Import data

In the first dialog box of the Import Wizard, you are asked to specify whether your data exists in a standard file format (e.g., Excel, Access, tab-delimited files, etc.)

Data files

The example below shows two equivalent ways to read data from a file on a diskette.

filename mydata 'a:\thesis.dat';
data thesis;
   infile mydata;
   input subjid group resp1-resp10;
data thesis;
   infile 'a:\thesis.dat';
   input subjid group resp1-resp10;

data items;
   infile data(items);
   input subjid group resp1-resp10;

data thesis;
   infile 'f:\work\sas\sasuser\thesis.dat';
   input subjid group resp1-resp10;

SAS files

• from the main SAS File menu, choose Open into Program Editor. A standard file selection panel will appear. Navigate through the Drive and Directory subwindows to select the file, then double-click or choose OK.
• type and submit a %include statement in the Program Editor. Several public SAS directories are predefined, one of which is referred to as data. Access things there in this form:

  %include data(fitness);
  

  which will insert the contents of the file FITNESS.SAS. The name DATA is a synonym (fileref) for the directory n:\data.

Using an external editor

You can also use any other editor (e.g., Notepad) to edit SAS files then either (a) Open into Program Manager to run the program as a whole, or (b) Copy lines to the Windows clipboard. To submit lines from the clipboard, select Run -> Submit clipboard from the popup menu.

Reading SPSS files

To read an SPSS save file, issue a LIBNAME statement that specifies the SPSS engine, in the form,

LIBNAME libref SPSS 'd:path\filename';

LIBNAME thesis SPSS 'f:\work\spss\thesis.dat';

You can then refer to the data in any PROC/DATA step as follows:

proc print data=thesis._first_;

© 1995 Michael Friendly