SPSS® 12.0 Command Syntax Reference

Variable Formats
Variables 25
SPSS accepts two variable types: numeric and string (also referred to as alphanumeric).
Numeric values are stored internally as double-precision floating-point numbers and string
values as codes listed in the SPSS character set (see Appendix B). Variable formats
determine how SPSS reads raw data into storage and how it displays and writes values out.
Input and Output Formats
Values are read according to their input format and displayed on your terminal or written to
a file according to their output format. The input and output formats differ in several ways.
• The input format is either specified or implied on the DATA LIST, KEYED DATA LIST, or
other data definition commands. It is in effect only when SPSS builds cases in a working
data file. Figure 8 shows the command printback for DATA LIST, which includes
input format specifications.
Figure 8 Output showing input formats
1 0 DATA LIST /ID 1-4 SCORE 6-9 (F,2).
This command will read 1 records from the command file
Variable Rec Start End Format
ID 1 1 4 F4.0
SCORE 1 6 9 F4.2
• DATA LIST or any other data definition command automatically generates an output format
from the input format and expands the output format to include punctuation characters
such as decimal points, commas, dollar signs, and percent signs. To see the current output
formats of variables in the working data file, use DISPLAY VARIABLES. The variables
defined by the above DATA LIST command are displayed in Figure 9. Note that the output
format for SCORE has been expanded one space to allow the display of the decimal point
(the F4.2 input format indicates a four-character variable with two implied decimal places;
the F5.2 output format includes one space for the decimal point).
Figure 9 Output showing output formats
List of variables on the active file
Name Pos Print Fmt Write Fmt Missing Values
ID 1 F4 F4
SCORE 2 F5.2 F5.2
• The formats (specified or default) on NUMERIC, COMPUTE, or other commands that
create new variables are output formats. You must specify adequate widths to
accommodate all punctuation characters.
• The output format is in effect during the entire working session (unless explicitly
changed) and is saved in the dictionary of an SPSS-format data file.
• Output formats for numeric variables can be changed with the FORMATS, PRINT FORMATS,
or WRITE FORMATS command.