AreaUnderCurveTest.java

/*
 * Copyright [2013-2015] PayPal Software Foundation
 *
 * Licensed 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 ml.shifu.shifu.core.evaluation;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;

import ml.shifu.shifu.container.PerformanceObject;
import ml.shifu.shifu.core.eval.AreaUnderCurve;
import ml.shifu.shifu.core.eval.PerformanceExtractor;
import ml.shifu.shifu.core.eval.Performances;

import org.testng.Assert;
import org.testng.annotations.BeforeClass;
import org.testng.annotations.Test;

public class AreaUnderCurveTest {
  
    private List<PerformanceObject> roc = new ArrayList<PerformanceObject>();
    private List<PerformanceObject> pr = new ArrayList<PerformanceObject>();
    
    @BeforeClass
    public void setUp() {
        double[][] rocPoints = new double[][] {
                {0.0, 0.0}, {0.5, 0.6}, {1.0, 1.0}
        };
        
        double[][] rocWeightedPoints = new double[][] {
                {0.0, 0.0}, {0.4, 0.6}, {1.0, 1.0}
        };
        
        double[][] prPoints = new double[][] {
                {0.0, 1.0}, {0.5, 0.6}, {1.0, 0.0}
        };
        
        double[][] prWeightedPoints = new double[][] {
                {0.0, 1.0}, {0.6, 0.4}, {1.0, 0.0}
        };
        
        for(int i = 0; i < rocPoints.length; i++) {
            PerformanceObject obj = new PerformanceObject();
            obj.fpr = rocPoints[i][0];
            obj.recall = rocPoints[i][1];
            obj.weightedFpr = rocWeightedPoints[i][0];
            obj.weightedRecall = rocWeightedPoints[i][1];
            roc.add(obj);
        }
        
        for(int i = 0; i < prPoints.length; i++) {
            PerformanceObject obj = new PerformanceObject();
            obj.recall = prPoints[i][0];
            obj.precision = prPoints[i][1];
            obj.weightedRecall = prWeightedPoints[i][0];
            obj.weightedPrecision = prWeightedPoints[i][1];
            pr.add(obj);
        }
    }
    
    @Test
    public void calculateAreaTest() {
        PerformanceExtractor xExtractor = Performances.fpr();
        PerformanceExtractor yExtractor = Performances.recall();
        List<PerformanceObject> nullList = null;
        List<PerformanceObject> oneList = Arrays.asList(new PerformanceObject());
        
        Assert.assertEquals(AreaUnderCurve.calculateArea(nullList, xExtractor, yExtractor), 0.0);
        Assert.assertEquals(AreaUnderCurve.calculateArea(oneList, xExtractor, yExtractor), 0.0);
    }
    
    @Test
    public void trapezoidTest() {
        double area = AreaUnderCurve.trapezoid(1, 1, 3, 4);
        Assert.assertEquals(area, 5.0);
    }
    
    @Test 
    void ofRocTest() {
        double area = AreaUnderCurve.ofRoc(roc);
        double weightedArea = AreaUnderCurve.ofWeightedRoc(roc);
        Assert.assertEquals(area, 0.55);
        Assert.assertEquals(weightedArea, 0.6);
    }
    
    @Test 
    void ofPrTest() {
        double area = AreaUnderCurve.ofPr(pr);
        double weightedArea = AreaUnderCurve.ofWeightedPr(pr);
        Assert.assertEquals(area, 0.55);
        Assert.assertEquals(weightedArea, 0.5);
    }
}