SPSS® 12.0 Command Syntax Reference

Variables 33
RBw (real binary):
The RB format is used to read data values that contain internal format floating-point
numbers. Such numbers are generated by COBOL using COMPUTATIONAL–1 or
COMPUTATIONAL–2 data items, by PL/I using FLOATING DECIMAL data items, by
FORTRAN using REAL or REAL*8 data items, or by Assembler using floating-point
data items.
The general syntax of the RB format is RBw, where w is the total number of bytes. The width
specification must be an even number between 2 and 8. Normally, a width specification of 8 is
used to read double-precision values, and a width of 4 is used to read single-precision values.
RBHEXw (hexadecimal of RB):
The RBHEX format interprets a series of hexadecimal characters as a number that represents
a floating-point number. This representation is system-specific. If the field width is less than
twice the width of a floating-point number, the value is right-padded with binary zeros. For
some operating systems (for example, IBM CMS), letters in hexadecimal values must be
upper case.
The general syntax of the RBHEX format is RBHEXw, where w indicates the total number
of columns. The width must be an even number. The values are real (floating-point) numbers.
Leading and trailing blanks are not allowed. Any data values shorter than the specified
input width must be padded with leading zeros.
String Variable Formats
• The values of string variables can contain numbers, letters, and special characters and can
be up to 255 characters long.
• SPSS differentiates between long strings and short strings. Long strings can be displayed
by some procedures and by the PRINT command, and they can be used as break variables
to define subgroups in REPORT. They cannot, however, be tabulated in procedures such
as CROSSTABS, and they cannot have user-missing values. Short strings, on the other
hand, can be tabulated and can have user-missing values. The maximum length of a short
string depends on the computer and operating system; it is typically 8 characters.
• System-missing values cannot be generated for string variables, since any character is a
legal string value.
• When a transformation command that creates or modifies a string variable yields a missing
or undefined result, a null string is assigned. The variable displays as blanks and is not
treated as missing.
• String formats are used to read and write string variables. The input values can be
alphanumeric characters (A format) or the hexadecimal representation of alphanumeric
characters (AHEX format).
• For fixed data, the width can be explicitly specified on DATA LIST or KEYED DATA LIST or
implied if column-style specifications are used. For freefield data, the default width is 1;
if the input string may be longer, w must be explicitly specified. Input strings shorter than
the specified width are right-padded with blanks.