org.debellor.base.evaluator
Class EvaluatorCell

java.lang.Object
  org.debellor.core.Cell
      org.debellor.base.evaluator.EvaluatorCell

Direct Known Subclasses:

CrossValidation, TrainAndTest

public class EvaluatorCell
extends Cell

Base class for cells that implement evaluation of other cells -- decision systems. To run evaluation you must insert the evaluated cell with either EvaluatorCell(Cell) or setInner(Cell), set the data source with Cell.setSource(Cell) and call Cell.learn() which performs actual evaluation. Afterwards you may read the result with either result() or report(). If you want to use the same instance of EvaluatorCell to run another evaluation you must call Cell.erase() first. Note that usually the evaluated cell must be erasable (it must correctly override Cell.onErase()).

Parameters:

• score: score type, name of the Score class to be used to measure quality of the evaluated decision system. Currently either "Accuracy" (for classification problems) or "RMSE" (root mean squared error, for regression problems). Default: "Accuracy". Score instance of a different type can be set manually with setScore(Score). Note that manual setting of Score instance takes effect only on the nearest invocation of learn, as opposed to specifying the score type through a parameter, which is effective on all consecutive calls to learn until the parameter is explicitly changed.

Author:

Marcin Wojnarski

See Also:

TrainAndTest, CrossValidation

Nested Class Summary

Nested classes/interfaces inherited from class org.debellor.core.Cell

Cell.CellMethod, Cell.State, Cell.Stream

Field Summary

protected Cell	learner
protected Score	score
protected Score	scoreFromUser

Fields inherited from class org.debellor.core.Cell

parameters, random

Constructor Summary

EvaluatorCell()

EvaluatorCell(Cell cell)

Method Summary

protected void	initScore()
protected void	onErase() Called by Cell.erase().
protected void	releaseData()
java.lang.String	report()
java.lang.Double[]	result()
void	setInner(Cell cell) Sets the cell - a decision system - that would undergo evaluation.
void	setScore(Score sc) Sets Score instance that will be used for calculation of a quality measure of the evaluated decision system.

Methods inherited from class org.debellor.core.Cell

close, erase, getAvailableParams, getParameters, learn, newThread, newThread, next, onClose, onLearn, onNext, onOpen, open, openInputStream, set, set, set, set, setAvailableParams, setParameters, setRandomSeed, setSource, state, toString

Methods inherited from class java.lang.Object

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

Field Detail

score

protected Score score

scoreFromUser

protected Score scoreFromUser

learner

protected Cell learner

Constructor Detail

EvaluatorCell

public EvaluatorCell()

EvaluatorCell

public EvaluatorCell(Cell cell)

Method Detail

setInner

public void setInner(Cell cell)

Sets the cell - a decision system - that would undergo evaluation.

setScore

public void setScore(Score sc)

Sets Score instance that will be used for calculation of a quality measure of the evaluated decision system. This method is an alternative for specifying the score type through the cell parameter "score", which is a preferred way of doing this. If both this method has been called and the parameter has been set, the score instance passed to this method is used.

Supplied score instance will be used only in the nearest call to learn. The score will not be reset at the beginning of evaluation, so the user may supply a previously-used score, in order to accumulate results of different evaluations.

initScore

protected void initScore()
                  throws IllegalParameterValueException

Throws:

IllegalParameterValueException

releaseData

protected void releaseData()

result

public java.lang.Double[] result()

report

public java.lang.String report()

onErase

protected void onErase()
                throws java.lang.Exception

Description copied from class: Cell

Called by Cell.erase(). Performs the actual erasure of cell content, while erase checks only against access violation and handles exceptions. Must be overridden in subclasses if erasure is to be used. Overriders may assume that the cell is in Cell.State.CLOSED state.

Overrides:

onErase in class Cell

Throws:

java.lang.Exception