variable formats

Variable Formats in SPSS Syntax

October 21st, 2010 by

One of the places that SPSS syntax excels at efficiency is when you’re creating new variables.  This is especially true when you’re creating a LOT of new variables, but even one or two can be quicker if you write the syntax code instead of menus.

And just as importantly, you’ll have documentation for exactly how you created them. (You think you’ll remember now, but 75 new variables later, you’ll thank me).

So once you create a new variable, you should of course immediately assign a Variable Label, and if appropriate, Value Labels and Missing Data Codes using Syntax.

Another thing that helps keep your new variable clean and interpretable is to assign the format.  The default format is F8.2, which indicates a numerical value

You could go into the Variable View screen and manually change the Width and Decimals columns, which indicate how many characters go before and after (for numeric variables) the decimal point.

But why do all that when you can just use a single command to define multiple variables?

The syntax command is FORMATS.  Here is the command for some common formats:

FORMATS NumVar1 NumVar2 (F5.0)
/NumVar3 (F6.1)
/StringVar1 (A15).

You can see the FORMATS command is followed by the variable names, then the format in parentheses.

Numeric variables NumVar1 and Numvar2 will both get the same format: with 5 digits, and nothing after the decimal.

Numeric variable NumVar3 will have 6 digits total, with one after the decimal.

And string variable (i.e. its value contain letters) StringVar1 is 15 characters wide.

This will get you started, but you can get all the specifics in the FORMATS section of the  Command Syntax Reference, which is included in the SPSS help.

[Note: Edited explanation of F6.1 to be 6 digits total, not 6 digits before the decimal).