CODEWITHSUNDEEP
sas
J.Z.
J.Z.

Reputation: 435

What does a dot do when it appears after a variable on the row of FORMAT in PROC FREQ in sas?

I wonder what does the IQ. on the row of FORMAT (second to the last row) does in this piece of codes? Does it mean a termination of variable name? Or does it mean a transformation to integer? Or something else? Thank you!

The dataset is called IQ, and it contains only one numerical variable called IQ. These numbers appear to be integers.

PROC FORMAT;
VALUE IQ 
75 - <85 = '75 <= IQ score < 85' 
85 - <95 = '85 <= IQ score < 95' 
95 - <105 = '95 <= IQ score < 105' 
105 - <115 = '105 <= IQ score < 115' 
115 - <125 = '115 <= IQ score < 125' 
125 - <135 = '125 <= IQ score < 135' 
135 - <145 = '135 <= IQ score < 145' 
145 - <155 = '145 <= IQ score < 155' 
; 
RUN; 

/* *************************** Frequency table of the grouped IQ score **************************** */ 
PROC FREQ DATA = IQ; 
TABLES IQ; 
FORMAT IQ IQ.; 
RUN;

Upvotes: 0

Views: 193

Answers (2)

Kermit
Kermit

Reputation: 3117

Look in your code to see if there is any reference to a PROC FORMAT. Although SAS provides a large number of ready made FORMATS and INFORMATS, it is often necessary to create formats designed for a specific purpose.
They can be created through PROC FORMAT and can be used to:

  • convert numeric variables into character values
  • convert character strings into numbers
  • convert character strings into other character strings

In your case, the user-defined format IQ. will convert the numeric variable iq to character values.

data have;
input iq iq_fmt;
format iq_fmt iq.;
cards;
80 80
100 100
110 110
130 130
150 150
;

  iq            iq_fmt
  80      75 <= IQ score < 85
 100      95 <= IQ score < 105
 110      105 <= IQ score < 115
 130      125 <= IQ score < 135
 150      145 <= IQ score < 155

Simple formats are created using the VALUE statement of the PROC FORMAT. It includes the name of the format to be created and the paired mapping of values (on the left of the = sign) and what those values will be mapped to (on the right of the = sign). As an example, if the value is between 75 and 85 (not incl.) the resulting value will be 75 <= IQ score < 85

In the above example, iq and iq_fmt are identical columns. I apply the IQ. format to the iq_fmt column. You can see that, for the first observation, the value of iq is 80, thus mapped to 75 <= IQ score < 85 in the iq_fmt column.

More details available in Building and Using User Defined Formats

Upvotes: 1

Tom
Tom

Reputation: 51566

The syntax for a FORMAT specification is the format name followed by an optional width followed by a period followed by an option decimal width.

A variable name cannot contain a period, so the PERIOD is what allows SAS to recognize that as a FORMAT specification instead of another variable name.

The FORMAT statement is used to attach a FORMAT specification to one or more VARIABLES. In your statement:

 FORMAT IQ IQ. ;

The list of variables is just the single variable IQ and the format to be applied is IQ. , which will use the default width defined with the IQ format since there is no width listed.

Upvotes: 1

Related Questions