org.apache.mahout.cf.taste.impl.eval.IRStatisticsImpl Maven / Gradle / Ivy
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* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
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* See the License for the specific language governing permissions and
* limitations under the License.
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package org.apache.mahout.cf.taste.impl.eval;
import java.io.Serializable;
import org.apache.mahout.cf.taste.eval.IRStatistics;
import com.google.common.base.Preconditions;
public final class IRStatisticsImpl implements IRStatistics, Serializable {
private final double precision;
private final double recall;
private final double fallOut;
private final double ndcg;
private final double reach;
IRStatisticsImpl(double precision, double recall, double fallOut, double ndcg, double reach) {
Preconditions.checkArgument(Double.isNaN(precision) || (precision >= 0.0 && precision <= 1.0),
"Illegal precision: " + precision + ". Must be: 0.0 <= precision <= 1.0 or NaN");
Preconditions.checkArgument(Double.isNaN(recall) || (recall >= 0.0 && recall <= 1.0),
"Illegal recall: " + recall + ". Must be: 0.0 <= recall <= 1.0 or NaN");
Preconditions.checkArgument(Double.isNaN(fallOut) || (fallOut >= 0.0 && fallOut <= 1.0),
"Illegal fallOut: " + fallOut + ". Must be: 0.0 <= fallOut <= 1.0 or NaN");
Preconditions.checkArgument(Double.isNaN(ndcg) || (ndcg >= 0.0 && ndcg <= 1.0),
"Illegal nDCG: " + ndcg + ". Must be: 0.0 <= nDCG <= 1.0 or NaN");
Preconditions.checkArgument(Double.isNaN(reach) || (reach >= 0.0 && reach <= 1.0),
"Illegal reach: " + reach + ". Must be: 0.0 <= reach <= 1.0 or NaN");
this.precision = precision;
this.recall = recall;
this.fallOut = fallOut;
this.ndcg = ndcg;
this.reach = reach;
}
@Override
public double getPrecision() {
return precision;
}
@Override
public double getRecall() {
return recall;
}
@Override
public double getFallOut() {
return fallOut;
}
@Override
public double getF1Measure() {
return getFNMeasure(1.0);
}
@Override
public double getFNMeasure(double b) {
double b2 = b * b;
double sum = b2 * precision + recall;
return sum == 0.0 ? Double.NaN : (1.0 + b2) * precision * recall / sum;
}
@Override
public double getNormalizedDiscountedCumulativeGain() {
return ndcg;
}
@Override
public double getReach() {
return reach;
}
@Override
public String toString() {
return "IRStatisticsImpl[precision:" + precision + ",recall:" + recall + ",fallOut:"
+ fallOut + ",nDCG:" + ndcg + ",reach:" + reach + ']';
}
}