The INFILE Statement by HC120218023948

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									The INFILE Statement

Reading files into SAS from an
      outside source:
    A Very Useful Tool!
Often the data you want to use are in
  an outside source, such as an Excel
  spreadsheet or text editor. You can
  import these data into SAS with the
  INFILE statement, rather than typing
  in all of the data by hand.
In addition to coming from different
  sources, the data may be delimited by
  spaces, tabs, or commas. There are
  codes to tell SAS what type of data it
  will be reading into the Editor.
            Basic SAS Code
The program you will use to read in a data
  file will follow this basic format, with slight
  variations:
DATA name of data set;
      INFILE ‘C:\location and name of file’ ;
      INPUT var1 var2 etc.;
RUN;
Let’s try a couple of examples.
    Space delimited data with no
    missing values and no labels
This will be the simplest type of data set you
 could encounter. Download the file called
 relief.txt, and save it to your hard drive
 where you will be able to easily locate it.
Open SAS and type the following code into
 your Editor window, keeping in mind that
 the path to the file may be different on
 your computer:
            Sample Code
DATA relieftime;
 INFILE ‘C:\Documents and Settings\My
 Documents\relief.txt’ ;
 INPUT group $ time;
 TITLE ‘Reading in Data from an External
 File’ ;
 PROC PRINT DATA = relieftime;
RUN;
• The first line creates a data set called relieftime.
• The INFILE statement tells SAS where to find
  the dataset.
• The third line labels the two variables in the data
  set (just as you have seen before).
• The TITLE statement gives anything you print a
  title.
• The PRINT statement prints your data in the
  Output window, so that you can make sure you
  did not lose any data.
• Try running the program in SAS. Were you
  successful? Check your log for any ERROR
  messages and try running the program again.
 Check your log for valuable information. It tells
you how many observations were read into SAS,
  and you can see if you are missing any data.
Output of PROC PRINT
Comma delimited data with missing
 values and labels in the first row
You will also encounter comma-separated value (csv) files,
  which are often created using Excel. To read in this type
  of data, you will need to use the DSD option in your SAS
  code.
Save the file about blood pressure (bp.csv) to your hard
  drive, then type the following code into your Editor
  window, keeping in mind the path to your file may be
  different from the example.
Before you read the file into SAS, open it and look at the
  format. Notice that first row contains variable names and
  there are a few missing values. We will address that
  using various SAS statements.
                     SAS Code
DATA bp;
   INFILE 'C:\Documents and Settings\My Documents\bp.csv'
   dlm = ',' dsd firstobs=2;
   INPUT clinic $ dbp6 sbp6 dbpbl sbpbl;
   TITLE 'Reading in .CSV Data from an External File';
   PROC PRINT DATA = bp;
RUN;
• dlm [delimiter] = ‘,’ tells SAS that the data is delimited by
  commas.
• dsd (delimiter-sensitive data) allows SAS to read in a
  .csv file. This also allows SAS to recognize the missing
  data.
• firstobs = 2 tells SAS to start reading the data from the
  second row (because the first row contains variable
  labels).
SAS Log
PROC PRINT Output
         Tab delimited Data
Other types of data may be tab delimited,
 and this is specified in the dlm option. We
 use the statement dlm = ’09’x. (’09’x is the
 hexadecimal representation of the tab
 character, but you don’t need to know that;
 it’s basically the technical way of
 specifying TAB as the delimiter.)
Download the file aplastic.txt, open it to see
 that the data begin on the first line, then
 read the file into SAS.
     SAS Code for Tab Delimited Data
DATA practice;
    INFILE 'C:\Documents and Settings\My Documents\aplastic.txt'
    dlm = '09'x firstobs=1;
    INPUT ret lymph;
    TITLE 'Reading in Tab-Delimited Data from an External File';
    PROC PRINT DATA = practice;
RUN;



 •   After running this program, check your SAS log.
 •   Are there any Errors or Warnings?
 •   If not, look at your Output.
 •   Is any data missing?
SAS Log
PROC PRINT Output
                Conclusions
These are just a few examples of the most
  common types of files you may encounter when
  reading in an external data file into SAS using
  the INFILE statement.
This skill will be valuable for future tutorials and
  homework assignments.
Here are some helpful links for more info:
UCLA Academic Technology Services
University of Michigan Software Help
University at Albany CSDA

								
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