User Guide

Chapter
7
Data Transfo
rmations
In an ideal situation, your raw data are perfectly suitable for the type of analysis you
want to perf
orm, and any relationships between variables are either conveniently
linear or neatly orthogonal. Unfortunately, this is rarely the case. Preliminary analysis
may reveal inconvenient coding schemes or coding errors, or data transformations
may be requ
ired in order to expose the true relationship between variables.
You can perform data transformations ranging from simple tasks, such as
collapsing categories for analysis, to more advanced tasks, such as creating new
variables
based on complex equations and conditional statements.
Computing Variables
Use the Compute dialog box to compute values for a variable based on numeric
transfor
mations of other variables.
 You can c
ompute values for numeric or string (alphanumeric) variables.
 You c an c
reate new variables or replace the values of existing variables. For new
variables, you can also specify the variable type and label.
 You can compute values selectively for subsets of data based on logical conditions.
 You can use more than 70 built-in functions, including arithmetic functions,
statistical functions, distribution functions, and string functions.
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