org.grouplens.lenskit.eval.traintest

Class FunctionModelMetric

java.lang.Object

org.grouplens.lenskit.eval.traintest.FunctionModelMetric

All Implemented Interfaces:

Closeable, AutoCloseable, Metric<List<Object>>

public class FunctionModelMetric
extends Object
implements Metric<List<Object>>

Model metric backed by an arbitrary function.

Since:

1.1

Constructor Summary

Constructors

Constructor and Description
FunctionModelMetric(List<String> columns, Function<Recommender,List<Object>> func)

Method Summary

Modifier and Type	Method and Description
void	close()
List<Object>	createContext(Attributed algorithm, TTDataSet dataSet, Recommender recommender) Create the context for an experimental condition (algorithm/data set pair).
List<String>	getColumnLabels() Get labels for the aggregate columns output by this evaluator.
List<Object>	getResults(List<Object> context) Get the aggregate results from an accumulator.
List<String>	getUserColumnLabels() Get labels for the per-user columns output by this evaluator.
List<Object>	measureUser(TestUser user, List<Object> context) Measure a user in the evaluation.

Methods inherited from class java.lang.Object

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

Constructor Detail

FunctionModelMetric

public FunctionModelMetric(List<String> columns,
                           Function<Recommender,List<Object>> func)

Method Detail

getColumnLabels

public List<String> getColumnLabels()

Description copied from interface: Metric

Get labels for the aggregate columns output by this evaluator.

Specified by:

getColumnLabels in interface Metric<List<Object>>

Returns:

The labels for this evaluator's output, used as column headers when outputting the results table.

getUserColumnLabels

public List<String> getUserColumnLabels()

Description copied from interface: Metric

Get labels for the per-user columns output by this evaluator.

Specified by:

getUserColumnLabels in interface Metric<List<Object>>

Returns:

The labels for this evaluator's per-user output, used as column headers when outputting the results table.

See Also:

Metric.measureUser(TestUser, Object)

createContext

public List<Object> createContext(Attributed algorithm,
                                  TTDataSet dataSet,
                                  Recommender recommender)

Description copied from interface: Metric

Create the context for an experimental condition (algorithm/data set pair).

Specified by:

createContext in interface Metric<List<Object>>

Parameters:

algorithm - The algorithm.

dataSet - The data set.

recommender - The LensKit recommender, if applicable. This can be null for an external algorithm that does not provide a LensKit recommender.

Returns:

The accumulator. This will be passed to Metric.measureUser(TestUser, Object). If the metric does not accumulate any results, this method can return null.

measureUser

@Nonnull
public List<Object> measureUser(TestUser user,
                                         List<Object> context)

Description copied from interface: Metric

Measure a user in the evaluation.

Specified by:

measureUser in interface Metric<List<Object>>

Parameters:

user - The user to evaluate.

context - The context for the active experimental condition.

Returns:

The table rows resulting from this user's measurement.

getResults

@Nonnull
public List<Object> getResults(List<Object> context)

Description copied from interface: Metric

Get the aggregate results from an accumulator.

Specified by:

getResults in interface Metric<List<Object>>

Parameters:

context - The context for an experimental condition.

Returns:

The aggregate results from the accumulator.

close

public void close()

Specified by:

close in interface Closeable

Specified by:

close in interface AutoCloseable