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attribute name role can be specified to indicate the column in the
dataset that has the attribute names and the attribute value role can
be specified to indicate the column that has the attribute values. In
addition to PhysicalDataSet, JDM defines PhysicalDataRecord to rep-
resent a single record that contains the PhysicalAttributes and associ-
ated attribute values for a single case. A PhysicalDataRecord instance
is used to apply a model on a single case. Section 9.4.6 will discuss
more about the single record apply.
For each physical attribute, there can be an associated logical
attribute specified in the logical data. In a LogicalAttribute object,
users can specify a list of values for a categorical attribute using a
CategorySet object. For example, one can specify the values {1, 2, 3, 4}
as the set of valid values for the Marital Status attribute and map
those values to unmarried, married, divorced, and widowed,
Section 4.5 introduced the concept of taxonomy as used by the
association function. We consider a taxonomy a data specification
object since it captures characteristics of the data used for model
JDM supports taxonomy representations as either external tables
or as native objects. Figure 8-3 depicts the taxonomy objects and
their relationships. Taxonomy is an abstract interface that general-
izes the two interfaces TaxonomyTable and TaxonomyObject . A Tax-
onomyTable object maps to an existing dataset containing the
taxonomy data. This design allows applications to maintain the
taxonomy separately from JDM and use the taxonomy in other
environments where table access via SQL may be necessary. A Tax-
onomyObject interface is used to create the taxonomy using the JDM
API. JDM provides full support for describing taxonomies as
objects when the sole use of the taxonomy is for mining with a
Figure 8-3
Taxonomy interfaces.
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