edu.uci.jforestsx.eval.BalancedYoundenIndex Maven / Gradle / Ivy
/**
* 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,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package edu.uci.jforestsx.eval;
import edu.uci.jforestsx.sample.Sample;
/**
* @author Yasser Ganjisaffar
*/
public class BalancedYoundenIndex extends EvaluationMetric {
private static final double THRESHOLD = 0.5;
public BalancedYoundenIndex() {
super(true);
}
@Override
public double measure(double[] predictions, Sample sample) {
int tp = 0;
int tn = 0;
int fn = 0;
int fp = 0;
for (int i = 0; i < sample.size; i++) {
double target = sample.targets[i];
double pred = predictions[i];
if (target > THRESHOLD) {
if (pred > THRESHOLD) {
tp++;
} else {
fn++;
}
} else {
if (pred > THRESHOLD) {
fp++;
} else {
tn++;
}
}
}
double sensitivity = (double) tp / (tp + fn);
double specificity = (double) tn / (tn + fp);
return Math.min(sensitivity, specificity);
}
}