Statistical Methods and Computing 22S 30 105 Instructor Cowles Lab 1 Jan 26 2011 1 Using SAS outside of ITCs You can access SAS from off campus by using the ITC Virtual Desktop Go to Note that this list is case sensitive with all files with names beginning with capital letters appearing before all other files If you are going to work with SAS on the Virtual Desktop it is easiest to copy and paste the data from the web page directly into the SAS program If you are running SAS on the computer at which you are sitting it is preferable to download the dataset into a file and tell SAS where to find the file Below I will show you how to have SAS access data both ways To download a data file for use in this lab itc uiowa edu Right click the file name use the right not left mouse button and click on Virtual Desktop You will be prompted to assent to an agreement and to enter your Hawkid and password Select the SAS 9 folder and from it SAS 9 1 3 SAS will come up on your screen When you are finished you must both exit from SAS and log off from the Virtual Desktop When you run SAS this way although you can interact with it on your screen it is actually running on a computer on campus Consequently SAS can t access files that are on your hard drive unless you specify drive letter mapping In this lab I will show you the most reliable way to get data into SAS when you are running it on the Virtual Desktop 2 Getting started in the ITC In the dialog box that opens left click Save target as use the left mouse button In the save as dialog box chose My Computer Local Disk C Temp Click Save If you preferred to save the file on your own disk in drive A so that you could use it on a different computer later you would move to drive A in the dialog box before saving Left click the billion info file to read a description of the billion dataset Click Back to get back to the list of datasets Then download the file billion dat according to the directions above ITC computers will display a login screen Users should enter their HawkID and password in the spots provided Students can find their HawkID and default passwords on the ISIS system 4 3 Lecture notes homework assignments and lab handouts are posted under Handouts These are in a format that may be read and printed in most ITCs Downloading files from the course web page Bring up a web browser either Firefox or Internet Explorer Enter the address of my web page in the location box www stat uiowa edu kcowles Other useful features on the course web page Return to the main course web page and click Web resources Note that there is a directory of the locations and hours of all the campus ITCs 5 Accessing SAS To access SAS on your own laptop go to Then click on Course homepages and 22S 30 105 Click on Datasets and when the next screen appears click on the underlined link Datasets Three types of files may be accessed Files ending in dat are data files for your use with the software package SAS Files ending in info contain descriptive information about datasets Files ending in txt are datasets for use in a different class with a different software package https virtualdesktop uiowa edu Log in with your Hawkid and password then choose SAS and SAS 9 2 To access SAS in the ITCs click on Start All Programs SAS SAS 9 2 This actually takes you to the Virtual Desktop as described above In either case you will get a screen that shows a menu bar a log window a program editor window 1 2 6 10 Entering commands and programs Reading data in from an existing datafile Click in the program editor window You may now type commands and programs in this window You have saved the file billion dat in the temp directory Use an infile statement to tell SAS to use it 7 data billion infile c temp billion dat input wlth age region How SAS programs and commands are organized Use a DATA step to organize your data by creating a SAS dataset Then use PROC steps or automated features to analyze your data Once you have created a SAS dataset you may apply any SAS procedures or automated features to it during the SAS session without recreating the dataset DATA and PROC steps consist of SAS statements Each statement must end with a semicolon Most statements include one or more keywords that must be spelled exactly as shown 8 The DATA step Creating a SAS dataset run 11 a column for each variable You must choose a name for the entire dataset and a name for each variable SAS has the following rules for names SAS names must begin with a letter or an underscore The remaining characters in a SAS name can be letters numbers or underscores There must be no embedded blanks SAS distinguishes between two types of variables numeric variables which contain only digits and decimal points and with which arithmetic operations may be done and character variables all other kinds of data 9 Controlling print width Put this line at the beginning of every SAS program if you want output to print correctly on 8 1 2 by 11 inch paper options linesize 75 gives dataset a name for SAS tells SAS where the data is names the variables in each row after region identifies character vbl end of data step Copying data directly into the data step In this alternative method to get data into SAS do not use an infile statement Instead use the datalines statement and copy and paste the data in immediately following it Put a semicolon all by itself on the line after the last line of data data billion input wlth age region Before it can process data SAS must read in the data in the form of a table with a row for each observation datalines 37 50 M 24 88 U 14 64 A 1 59 E 1 E 1 O run gives dataset a name for SAS names the variables in each row after region identifies character vbl end of data step Type one of these data steps into the program editor window To make SAS run these statements and create the dataset use the mouse to highlight the block of statements and then click on the icon of the running man SAS will use the log window to tell you what it has done Be sure to check the log window for any error messages If any errors are reported click in the program editor window to make it active Correct the errors in the code and then rerun the block of code Note if you wanted to read in the file from your own disk in the A drive the infile statement …