weka.experiment
Interface ResultListener

All Superinterfaces:

java.io.Serializable

All Known Implementing Classes:

AveragingResultProducer, CSVResultListener, DatabaseResultListener, LearningRateResultProducer

public interface ResultListener

extends java.io.Serializable

Interface for objects able to listen for results obtained by a ResultProducer

Version:

$Revision: 1.6 $

Author:

Len Trigg (trigg@cs.waikato.ac.nz)

Method Summary

void	acceptResult(ResultProducer rp, java.lang.Object[] key, java.lang.Object[] result) Accepts results from a ResultProducer.
java.lang.String[]	determineColumnConstraints(ResultProducer rp) Determines if there are any constraints (imposed by the destination) on additional result columns to be produced by resultProducers.
boolean	isResultRequired(ResultProducer rp, java.lang.Object[] key) Determines whether the results for a specified key must be generated.
void	postProcess(ResultProducer rp) Perform any postprocessing.
void	preProcess(ResultProducer rp) Prepare for the results to be received.

Method Detail

determineColumnConstraints

public java.lang.String[] determineColumnConstraints(ResultProducer rp)
                                              throws java.lang.Exception

Determines if there are any constraints (imposed by the destination) on additional result columns to be produced by resultProducers. Null should be returned if there are NO constraints, otherwise a list of column names should be returned as an array of Strings.

Parameters:

rp - the ResultProducer to which the constraints will apply

Returns:

an array of column names to which resutltProducer's additional results will be restricted.

Throws:

java.lang.Exception - if an error occurs

preProcess

public void preProcess(ResultProducer rp)
                throws java.lang.Exception

Prepare for the results to be received.

Parameters:

rp - the ResultProducer that will generate the results

Throws:

java.lang.Exception - if an error occurs during preprocessing.

postProcess

public void postProcess(ResultProducer rp)
                 throws java.lang.Exception

Perform any postprocessing. When this method is called, it indicates that no more results will be sent that need to be grouped together in any way.

Parameters:

rp - the ResultProducer that generated the results

Throws:

java.lang.Exception - if an error occurs

acceptResult

public void acceptResult(ResultProducer rp,
                         java.lang.Object[] key,
                         java.lang.Object[] result)
                  throws java.lang.Exception

Accepts results from a ResultProducer.

Parameters:

rp - the ResultProducer that generated the results

key - an array of Objects (Strings or Doubles) that uniquely identify a result for a given ResultProducer with given compatibilityState

result - the results stored in an array. The objects stored in the array may be Strings, Doubles, or null (for the missing value).

Throws:

java.lang.Exception - if the result could not be accepted.

isResultRequired

public boolean isResultRequired(ResultProducer rp,
                                java.lang.Object[] key)
                         throws java.lang.Exception

Determines whether the results for a specified key must be generated.

Parameters:

rp - the ResultProducer wanting to generate the results

key - an array of Objects (Strings or Doubles) that uniquely identify a result for a given ResultProducer with given compatibilityState

Returns:

true if the result should be generated

Throws:

java.lang.Exception - if it could not be determined if the result is needed.