/*
    * 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
    *
    *      https://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.
   */
  
  /*
   * This is not the original file distributed by the Apache Software Foundation
   * It has been modified by the Hipparchus project
   */
  
  package org.hipparchus.distribution.continuous;
  
  import static org.junit.Assert.assertEquals;
  import static org.junit.Assert.assertTrue;
  import static org.junit.Assert.fail;
  
  import org.hipparchus.exception.MathIllegalArgumentException;
  import org.junit.Test;
  
  /**
   * Test cases for CauchyDistribution.
   */
  public class CauchyDistributionTest extends RealDistributionAbstractTest {
  
      // --------------------- Override tolerance  --------------
      protected double defaultTolerance = 1e-9;
      @Override
      public void setUp() {
          super.setUp();
          setTolerance(defaultTolerance);
      }
  
      //-------------- Implementations for abstract methods -----------------------
  
      /** Creates the default continuous distribution instance to use in tests. */
      @Override
      public CauchyDistribution makeDistribution() {
          return new CauchyDistribution(1.2, 2.1);
      }
  
      /** Creates the default cumulative probability distribution test input values */
      @Override
      public double[] makeCumulativeTestPoints() {
          // quantiles computed using R 2.9.2
          return new double[] {-667.24856187, -65.6230835029, -25.4830299460, -12.0588781808,
                  -5.26313542807, 669.64856187, 68.0230835029, 27.8830299460, 14.4588781808, 7.66313542807};
      }
  
      /** Creates the default cumulative probability density test expected values */
      @Override
      public double[] makeCumulativeTestValues() {
          return new double[] {0.001, 0.01, 0.025, 0.05, 0.1, 0.999,
                  0.990, 0.975, 0.950, 0.900};
      }
  
      /** Creates the default probability density test expected values */
      @Override
      public double[] makeDensityTestValues() {
          return new double[] {
              1.49599158008e-06, 0.000149550440335, 0.000933076881878,
              0.00370933207799,  0.0144742330437,   1.49599158008e-06,
              0.000149550440335, 0.000933076881878, 0.00370933207799,
              0.0144742330437
          };
      }
  
      //---------------------------- Additional test cases -------------------------
  
      @Test
      public void testInverseCumulativeProbabilityExtremes() {
          setInverseCumulativeTestPoints(new double[] {0.0, 1.0});
          setInverseCumulativeTestValues(
                  new double[] {Double.NEGATIVE_INFINITY, Double.POSITIVE_INFINITY});
          verifyInverseCumulativeProbabilities();
      }
  
      @Test
      public void testMedian() {
          CauchyDistribution distribution = (CauchyDistribution) getDistribution();
          assertEquals(1.2, distribution.getMedian(), 0.0);
      }
  
      @Test
      public void testScale() {
          CauchyDistribution distribution = (CauchyDistribution) getDistribution();
          assertEquals(2.1, distribution.getScale(), 0.0);
      }
 
     @Test
     public void testPreconditions() {
         try {
             new CauchyDistribution(0, 0);
             fail("Cannot have zero scale");
         } catch (MathIllegalArgumentException ex) {
             // Expected.
         }
         try {
             new CauchyDistribution(0, -1);
             fail("Cannot have negative scale");
         } catch (MathIllegalArgumentException ex) {
             // Expected.
         }
     }
 
     @Test
     public void testMoments() {
         CauchyDistribution dist;
 
         dist = new CauchyDistribution(10.2, 0.15);
         assertTrue(Double.isNaN(dist.getNumericalMean()));
         assertTrue(Double.isNaN(dist.getNumericalVariance()));
 
         dist = new CauchyDistribution(23.12, 2.12);
         assertTrue(Double.isNaN(dist.getNumericalMean()));
         assertTrue(Double.isNaN(dist.getNumericalVariance()));
     }
 }