/*
* LensKit, an open source recommender systems toolkit.
* Copyright 2010-2014 LensKit Contributors. See CONTRIBUTORS.md.
* Work on LensKit has been funded by the National Science Foundation under
* grants IIS 05-34939, 08-08692, 08-12148, and 10-17697.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation; either version 2.1 of the
* License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
* FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
* details.
*
* You should have received a copy of the GNU General Public License along with
* this program; if not, write to the Free Software Foundation, Inc., 51
* Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*/
package org.grouplens.lenskit.eval.traintest;
import com.google.common.base.Function;
import com.google.common.base.Preconditions;
import com.google.common.collect.Lists;
import org.grouplens.lenskit.Recommender;
import org.grouplens.lenskit.eval.Attributed;
import org.grouplens.lenskit.eval.data.traintest.TTDataSet;
import org.grouplens.lenskit.eval.metrics.Metric;
import org.grouplens.lenskit.util.table.TableLayoutBuilder;
import org.grouplens.lenskit.util.table.writer.CSVWriter;
import org.grouplens.lenskit.util.table.writer.TableWriter;
import javax.annotation.Nonnull;
import javax.annotation.Nullable;
import java.io.File;
import java.io.IOException;
import java.util.Collections;
import java.util.List;
/**
* Model metric backed by an arbitrary function that returns multiple rows per algorithmInfo.
*
* @author <a href="http://www.grouplens.org">GroupLens Research</a>
* @since 1.1
*/
public class FunctionMultiModelMetric implements Metric<Void> {
private final File outputFile;
private final List<String> columnHeaders;
private final Function<Recommender, List<List<Object>>> function;
private TableWriter writer;
private ExperimentOutputLayout evalLayout;
public FunctionMultiModelMetric(File file, List<String> columns,
Function<Recommender, List<List<Object>>> func,
ExperimentOutputLayout layout) {
outputFile = file;
columnHeaders = Lists.newArrayList(columns);
function = func;
evalLayout = layout;
TableLayoutBuilder builder = TableLayoutBuilder.copy(evalLayout.getCommonLayout());
for (String col: columnHeaders) {
builder.addColumn(col);
}
try {
writer = CSVWriter.open(outputFile, builder.build());
} catch (IOException e) {
throw new RuntimeException("error opening output file", e);
}
}
@Override
public List<String> getColumnLabels() {
return Collections.emptyList();
}
@Override
public List<String> getUserColumnLabels() {
return Collections.emptyList();
}
@Nullable
@Override
public Void createContext(Attributed algorithm, TTDataSet dataSet, Recommender recommender) {
Preconditions.checkState(evalLayout != null, "evaluation not in progress");
TableWriter w = evalLayout.prefixTable(writer, algorithm, dataSet);
for (List<Object> row: function.apply(recommender)) {
try {
w.writeRow(row.toArray());
} catch (IOException e) {
throw new RuntimeException("error writing row", e);
}
}
return null;
}
@Nonnull
@Override
public List<Object> measureUser(TestUser user, Void context) {
return Collections.emptyList();
}
@Nonnull
@Override
public List<Object> getResults(Void context) {
return Collections.emptyList();
}
@Override
public void close() throws IOException {
writer.close();
}
public static class Factory extends MetricFactory<Void> {
private final File outputFile;
private final List<String> columns;
private final Function<Recommender, List<List<Object>>> function;
public Factory(File file, List<String> cols, Function<Recommender, List<List<Object>>> func) {
outputFile = file;
columns = cols;
function = func;
}
@Override
public Metric<Void> createMetric(TrainTestEvalTask task) {
return new FunctionMultiModelMetric(outputFile, columns, function,
task.getOutputLayout());
}
@Override
public List<String> getColumnLabels() {
return Collections.emptyList();
}
@Override
public List<String> getUserColumnLabels() {
return Collections.emptyList();
}
}
}