Run JesterRecommenderEvaluationRunner, but get no results of evaluation - mahout

Question

I downloaded the Jester example code in Mahout, and tries to run it on jester dataset to see the evaluation results. the running is done successfully, but the console only has the results:
log4j:WARN No appenders could be found for logger (org.apache.mahout.cf.taste.impl.model.file.FileDataModel).
log4j:WARN Please initialize the log4j system properly.
log4j:WARN See http://logging.apache.org/log4j/1.2/faq.html#noconfig for more info.
I expect to see the evaluation score range from 0 to 10. any one can help me found out how to get the score?
I am using mahout-core-0.6.jar and the following is the code:
JesterDataModel.java:
package Jester;
import java.io.File;
import java.io.IOException;
import java.util.Collection;
import java.util.regex.Pattern;
import com.google.common.collect.Lists;
import org.apache.mahout.cf.taste.example.grouplens.GroupLensDataModel;
import org.apache.mahout.cf.taste.impl.common.FastByIDMap;
import org.apache.mahout.cf.taste.impl.model.GenericDataModel;
import org.apache.mahout.cf.taste.impl.model.GenericPreference;
import org.apache.mahout.cf.taste.impl.model.file.FileDataModel;
import org.apache.mahout.cf.taste.model.DataModel;
import org.apache.mahout.cf.taste.model.Preference;
import org.apache.mahout.common.iterator.FileLineIterator;
//import org.apache.mahout.cf.taste.impl.common.FileLineIterable;
public final class JesterDataModel extends FileDataModel {
private static final Pattern COMMA_PATTERN = Pattern.compile(",");
private long userBeingRead;
public JesterDataModel() throws IOException {
this(GroupLensDataModel.readResourceToTempFile("\\jester-data-1.csv"));
}
public JesterDataModel(File ratingsFile) throws IOException {
super(ratingsFile);
}
#Override
public void reload() {
userBeingRead = 0;
super.reload();
}
#Override
protected DataModel buildModel() throws IOException {
FastByIDMap<Collection<Preference>> data = new FastByIDMap<Collection<Preference>> ();
FileLineIterator iterator = new FileLineIterator(getDataFile(), false);
FastByIDMap<FastByIDMap<Long>> timestamps = new FastByIDMap<FastByIDMap<Long>>();
processFile(iterator, data, timestamps, false);
return new GenericDataModel(GenericDataModel.toDataMap(data, true));
}
#Override
protected void processLine(String line,
FastByIDMap<?> rawData,
FastByIDMap<FastByIDMap<Long>> timestamps,
boolean fromPriorData) {
FastByIDMap<Collection<Preference>> data = (FastByIDMap<Collection<Preference>>) rawData;
String[] jokePrefs = COMMA_PATTERN.split(line);
int count = Integer.parseInt(jokePrefs[0]);
Collection<Preference> prefs = Lists.newArrayListWithCapacity(count);
for (int itemID = 1; itemID < jokePrefs.length; itemID++) { // yes skip first one, just a count
String jokePref = jokePrefs[itemID];
if (!"99".equals(jokePref)) {
float jokePrefValue = Float.parseFloat(jokePref);
prefs.add(new GenericPreference(userBeingRead, itemID, jokePrefValue));
}
}
data.put(userBeingRead, prefs);
userBeingRead++;
}
}
JesterRecommenderEvaluatorRunner.java
package Jester;
import org.apache.mahout.cf.taste.common.TasteException;
import org.apache.mahout.cf.taste.eval.RecommenderEvaluator;
import org.apache.mahout.cf.taste.impl.eval.AverageAbsoluteDifferenceRecommenderEvaluator;
import org.apache.mahout.cf.taste.model.DataModel;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.io.IOException;
public final class JesterRecommenderEvaluatorRunner {
private static final Logger log = LoggerFactory.getLogger(JesterRecommenderEvaluatorRunner.class);
private JesterRecommenderEvaluatorRunner() {
// do nothing
}
public static void main(String... args) throws IOException, TasteException {
RecommenderEvaluator evaluator = new AverageAbsoluteDifferenceRecommenderEvaluator();
DataModel model = new JesterDataModel();
double evaluation = evaluator.evaluate(new JesterRecommenderBuilder(),
null,
model,
0.9,
1.0);
log.info(String.valueOf(evaluation));
}
}

Answer 1

Mahout 0.7 is old, and 0.6 is very old. Use at least 0.7, or better, later from SVN.
I think the problem is exactly what you identified: you don't have any slf4j bindings in your classpath. If you use the ".job" files in Mahout you will have all dependencies packages. Then you will actually see output.