user manual

Chapter
7
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7
Building CLEM Expressions
About CLEM
The Control Language for Expression Manipulation (CLEM) is a powerful language for analyzing
and m anipulating the data that flows along IBM® SPSS® Modeler s treams. D ata miners use
CLEM extensively in stream operations to perform tasks as simple as deriving profit from cost
and revenue data or as complex as transforming web log data into a set of fields and records with
usable informati on.
CLEM is used
within SPSS Modeler to:
 Compare a nd evaluate conditions on record fields.
 Derive va l
ues for new fields.
 Derive ne w values for existing fields.
 Reason abo
ut the sequence of reco r ds.
 Insert data from records into repo r ts .
Scripting.
A subset of the CLEM languag e can also be used when sc r ipting in the user interface.
This allows you to perform many of th e same data manipulations in an automat ed fashion.
CLEM expres sions are indispensa ble for data preparatio n in SPSS Modeler and can be use d in
a wide range of nodes—from record and field operations (Select, Balance, Filler) to plots and
output (Analysis, Repo r t, Table). Fo r example, you can use CLEM in a Derive node to create a
new field based on a f ormula such as ratio.
© Copyright IBM Corporation 1994, 2012.
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