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kddml.Core.DataMining.ClassificationTrees.BooleanOperator Class Reference

List of all members.

Static Public Attributes

static final BooleanOperator AND = new BooleanOperator()
static final BooleanOperator OR = new BooleanOperator()
static final BooleanOperator XOR = new BooleanOperator()
static final BooleanOperator SURROGATE = new BooleanOperator()

Detailed Description

This enumeration specifies the comparison operator that associates two or more Predicate. The association is boolean: and, or, xor, or surrogate.
The operators and, or, and xor are associative binary operators, having their usual semantics. The order of evaluation is irrelevant for all the predicates within one compound predicate.
The operator 'surrogate' allows for specifing surrogate predicates. They are used for cases where a missing value appears in the evaluation of the parent predicate such that an alternative predicate is available. An expression 'surrogate(a,b)' is equivalent to 'if not unknown(a) then a else b'.

Title: KDDML

Description: Knowledge Discovery in Database Environment

Copyright: Copyright (c) 2003-2005

Company: Universita' di Pisa - Dipartimento di Informatica

Author:
Andrea Romei (romei@di.unipi.it)
Version:
2.0.16


Member Data Documentation

final BooleanOperator kddml.Core.DataMining.ClassificationTrees.BooleanOperator.AND = new BooleanOperator() [static]
 

And boolean operator.

true AND true --> true.
true AND false --> false.
false AND false --> false.
unknown AND true --> unknown.
unknown AND false --> false.
unknown AND unknown --> unknown.

final BooleanOperator kddml.Core.DataMining.ClassificationTrees.BooleanOperator.OR = new BooleanOperator() [static]
 

Or boolean operator.

true OR true --> true.
true OR false --> true.
false OR false --> false.
unknown OR true --> true.
unknown OR false --> unknown.
unknown OR unknown --> unknown.

final BooleanOperator kddml.Core.DataMining.ClassificationTrees.BooleanOperator.XOR = new BooleanOperator() [static]
 

The operator 'xor' is only used with two arguments only, it indicates an evaluation to TRUE if the predicates evaluate to different values (one TRUE and one FALSE).

true XOR true --> true.
true XOR false --> false.
false XOR false --> true.
true XOR unknown --> unknown.
false XOR unknown --> unknown.
unknown XOR unknown --> unknown.

final BooleanOperator kddml.Core.DataMining.ClassificationTrees.BooleanOperator.SURROGATE = new BooleanOperator() [static]
 

The surrogate operator. The operator surrogate provides a special means to handle logical expressions with missing values. It is applied to a sequence of predicates. The order of the predicates matters, the first predicate is the primary, the next predicates are the surrogates. Evaluation order is left-to-right. The cascaded predicates are applied when the primary predicate evaluates to 'Unknown'. Therefore, the surrogate predicates can provide a resolution to an undetermined predicate.


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