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kddml.Operators.Preprocessing.PP_REWRITING_RESOLVER Class Reference

Inheritance diagram for kddml.Operators.Preprocessing.PP_REWRITING_RESOLVER:

kddml.Operators.Preprocessing.PPAlgorithmLoaderResolver kddml.Operators.AlgorithmLoaderResolver kddml.Operators.OperatorResolver kddml.Operators.HWResourcesDescription List of all members.

Public Member Functions

void readAttributes (Hashtable< String, KDDMLScalarManager > parameters) throws KDDMLCoreException
KDDMLObject execute (Hashtable< String, KDDMLScalarManager > settings, Vector< KDDMLObject > arguments) throws ResolverException, KDDMLCoreException
kddml.Core.KDDMLObjectType getArgumentType (int i)
int estimatedRAMUsage ()

Detailed Description

The operator rewrites the values of an input table attribute. It is a construct based on regular expressions that are a powerful way to specify string matching and the substitution of some pattern with new values.
The operator takes a preprocessing table, a table attribute and a set of pairs containing a condition (element CONDITION) and a rewriting method (element ALGORITHM). It returns a new preprocessing table with rewritten values for the specified attribute.
The condition regards restrictions on the rows to be rewritten. In other words, the corresponding rewriting rule is applied only on instances on which the condition is satisfied. By using this strategy, more rewriting algorithm can be used on a single record. Each condition provides a constraint on these algorithms.
In general, every rewriting algorithm is characterized by three features:
  1. the regular expression used to match the input value;
  2. the replacement policy to apply when the matching succeeds (for example, it is possible to replace all string value or only some occurrences satisfying the pattern matching);
  3. the policy to apply when the matching procedure fails (typically, a preprocessing marking procedure is applied in this case).
The type of the rewriting attribute is preserved. Run-time checking is needed on new values for numeric or nominal attributes. In particular, nominal categories for an enumerated attribute must be preserved after rewriting.

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)

Sandra Zimei

Version:
2.0.16


Member Function Documentation

void kddml.Operators.Preprocessing.PP_REWRITING_RESOLVER.readAttributes Hashtable< String, KDDMLScalarManager parameters  )  throws KDDMLCoreException
 

Reads the XML attributes related to a generic preprocessing operator. An operator settings object captures the attributes associated with a particular operator. It allows a knowledgeable user to fine tune operator parameters. Generally, not all parameters must be specified, however, those specified are taken into account by the KDDML.
Attributes are given as hashtable, where the key is the name of the attribute related to the operator and the value is a KDDMLScalar object containing the attribute value. Attribute value is checked by the interpreter layer and its type is correct.

Parameters:
parameters Hashtable the attributes related to the operator. The key of the hashtable is the name of the operator. The value of the hashtable is a KDDMLScalar representing the value of the operator.
Exceptions:
ResolverException if a resolving error occurs.
KDDMLCoreException if a level core error occurs.

KDDMLObject kddml.Operators.Preprocessing.PP_REWRITING_RESOLVER.execute Hashtable< String, KDDMLScalarManager settings,
Vector< KDDMLObject arguments
throws ResolverException, KDDMLCoreException [virtual]
 

Overloading of the main execute method. Returns the result of evaluating the operator over the passed arguments and attributes.
Attributes are given as hashtable, where the key is the name of the XML attribute related to the operator and the value is a KDDMLScalar object containing the attribute value. Attribute value is checked by the interpreter layer and it is correct.
Arguments are given as vector of KDDMLOjbect. Types of arguments are correct, as required by the getArgumentType(int i) method.
Implementations of the execute method can be distinguished according to the type of operator.

Parameters:
settings Hashtable the attributes related to the operator. The key of the hashtable is the name of the attribute. The value of the hashtable is a KDDMLScalar representing the value of the attribute.
arguments Vector the list of arguments as KDDMLObject.
Returns:
KDDMLObject the result of evaluating the operator.
Exceptions:
ResolverException if a resolving error occurs.
KDDMLCoreException if a level core error occurs.

Implements kddml.Operators.OperatorResolver.

kddml.Core.KDDMLObjectType kddml.Operators.Preprocessing.PP_REWRITING_RESOLVER.getArgumentType int  i  )  [virtual]
 

Returns the expected type of the i-th argument of the operator. Returns null if the operator do not admit argument as i-th child.

Parameters:
i int
Returns:
KDDMLObjectType

Implements kddml.Operators.OperatorResolver.

int kddml.Operators.Preprocessing.PP_REWRITING_RESOLVER.estimatedRAMUsage  ) 
 

Returns the estimated RAM usage for the operator. Must be a value between 0 and 1024 MB.

Returns:
int default returns 256.

Reimplemented from kddml.Operators.OperatorResolver.


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