com.rapidminer.operator.preprocessing
Class GroupByOperator

java.lang.Object
  com.rapidminer.operator.Operator
      com.rapidminer.operator.preprocessing.GroupByOperator

All Implemented Interfaces:

ConfigurationListener, PreviewListener, ParameterHandler, LoggingHandler

public class GroupByOperator
extends Operator

This operator creates a SplittedExampleSet from an arbitrary example set. The partitions of the resulting example set are created according to the values of the specified attribute. This works similar to the GROUP BY clause in SQL.

Please note that the resulting example set is simply a splitted example set where no subset is selected. Following operators might decide to select one or several of the subsets, e.g. one of the aggregation operators.

Author:

Christian Bockermann, Ingo Mierswa

Field Summary

static java.lang.String

PARAMETER_ATTRIBUTE_NAME

Constructor Summary

GroupByOperator(OperatorDescription desc)

Method Summary

IOObject[]	apply() Implement this method in subclasses.
java.lang.Class<?>[]	getInputClasses() Returns the classes that are needed as input.
java.lang.Class<?>[]	getOutputClasses() Returns the classes that are guaranteed to be returned by apply() as additional output.
java.util.List<ParameterType>	getParameterTypes() Returns a list of ParameterTypes describing the parameters of this operator.

Methods inherited from class com.rapidminer.operator.Operator

addError, addValue, addWarning, apply, checkDeprecations, checkForStop, checkIO, checkProperties, clearErrorList, cloneOperator, createExperimentTree, createExperimentTree, createFromXML, createMarkedExperimentTree, createMarkedProcessTree, createProcessTree, createProcessTree, getAddOnlyAdditionalOutput, getApplyCount, getDeliveredOutputClasses, getDeprecationInfo, getDesiredInputClasses, getEncoding, getErrorList, getExperiment, getInnerOperatorsXML, getInput, getInput, getInput, getInputDescription, getIOContainerForInApplyLoopBreakpoint, getIODescription, getLog, getName, getOperatorClassName, getOperatorDescription, getParameter, getParameterAsBoolean, getParameterAsColor, getParameterAsDouble, getParameterAsFile, getParameterAsFile, getParameterAsInputStream, getParameterAsInt, getParameterAsMatrix, getParameterAsString, getParameterList, getParameters, getParameterType, getParent, getProcess, getStartTime, getStatus, getUserDescription, getValue, getValues, getXML, hasBreakpoint, hasBreakpoint, hasInput, inApplyLoop, isDebugMode, isEnabled, isExpanded, isParallel, isParameterSet, log, logError, logNote, logWarning, performAdditionalChecks, processFinished, processStarts, register, registerOperator, remove, rename, resume, setApplyCount, setBreakpoint, setEnabled, setExpanded, setInput, setListParameter, setOperatorParameters, setParameter, setParameters, setParent, setUserDescription, toString, unregisterOperator, writeXML

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

PARAMETER_ATTRIBUTE_NAME

public static final java.lang.String PARAMETER_ATTRIBUTE_NAME

See Also:

Constant Field Values

Constructor Detail

GroupByOperator

public GroupByOperator(OperatorDescription desc)

Method Detail

apply

public IOObject[] apply()
                 throws OperatorException

Description copied from class: Operator

Implement this method in subclasses.

Specified by:

apply in class Operator

Throws:

OperatorException

getInputClasses

public java.lang.Class<?>[] getInputClasses()

Description copied from class: Operator

Returns the classes that are needed as input. May be null or an empty (no desired input). As default, all delivered input objects are consumed and must be also delivered as output in both Operator.getOutputClasses() and Operator.apply() if this is necessary. This default behavior can be changed by overriding Operator.getInputDescription(Class). Subclasses which implement this method should not make use of parameters since this method is invoked by getParameterTypes(). Therefore, parameters are not fully available at this point of time and this might lead to exceptions. Please use InputDescriptions instead.

Specified by:

getInputClasses in class Operator

getOutputClasses

public java.lang.Class<?>[] getOutputClasses()

Description copied from class: Operator

Returns the classes that are guaranteed to be returned by apply() as additional output. Please note that input objects which should not be consumed must also be defined by this method (e.g. an example set which is changed but not consumed in the case of a preprocessing operator must be defined in both, the methods Operator.getInputClasses() and Operator.getOutputClasses()). The default behavior for input consumation is defined by Operator.getInputDescription(Class) and can be changed by overwriting this method. Objects which are not consumed (defined by changing the implementation in Operator.getInputDescription(Class)) must not be defined as additional output in this method.

May deliver null or an empy array (no additional output is produced or guaranteed). Must return the class array of delivered output objects otherwise.

Specified by:

getOutputClasses in class Operator

getParameterTypes

public java.util.List<ParameterType> getParameterTypes()

Description copied from class: Operator

Returns a list of ParameterTypes describing the parameters of this operator. The default implementation returns an empty list if no input objects can be retained and special parameters for those input objects which can be prevented from being consumed.

Specified by:

getParameterTypes in interface ParameterHandler

Overrides:

getParameterTypes in class Operator