SPSS® 12.0 Command Syntax Reference

534 EXPORT
MAP Subcommand
MAP displays any changes that have been specified by the RENAME, DROP, or KEEP
subcommands.
• MAP can be specified as often as desired.
• Each MAP subcommand maps the results of subcommands that precede it; results of
subcommands that follow it are not mapped.When MAP is specified last, it also produces
a description of the portable file.
Example
EXPORT OUTFILE=NEWSUM /DROP=DEPT TO DIVISION /MAP
/RENAME NAME=LNAME WAGE=SALARY /MAP.
• The first MAP subcommand produces a listing of the variables in the file after DROP has
dropped the specified variables.
• RENAME renames NAME and WAGE.
• The second MAP subcommand shows the variables in the file after renaming. Since this
is the last subcommand, the listing will show the variables as they are written in the
portable file.
DIGITS Subcommand
DIGITS specifies the degree of precision for all noninteger numeric values written to the
portable file.
• DIGITS has the general form DIGITS=n, where n is the number of digits of precision.
• DIGITS applies to all numbers for which rounding is required.
• Different degrees of precision cannot be specified for different variables. Thus, DIGITS
should be set according to the requirements of the variable that needs the most precision.
• Default precision methods used by EXPORT work perfectly for integers that are not too
large and for fractions whose denominators are products of 2, 3, and 5 (all decimals, quarters,
eighths, sixteenths, thirds, thirtieths, sixtieths, and so forth.) For other fractions and
for integers too large to be represented exactly in the working data file (usually more than
9 digits, often 15 or more), the representation used in the working file contains some error
already, so no exact way of sending these numbers is possible. The program sends enough
digits to get very close. The number of digits sent in these cases depends on the originating
computer: on mainframe IBM versions of the program, it is the equivalent of 13
decimal digits (integer and fractional parts combined). If many numbers on a file require
this level of precision, the file can grow quite large. If you do not need the full default
precision, you can save some space in the portable file by using the DIGITS subcommand.
Example
EXPORT OUTFILE=NEWSUM /DROP=DEPT TO DIVISION /MAP /DIGITS=4.
• DIGITS guarantees the accuracy of values to four significant digits. For example,
12.34567890876 will be rounded to 12.35.