/*
    * 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 org.apache.commons.math4.legacy.stat.inference;
  
  import org.apache.commons.math4.legacy.exception.DimensionMismatchException;
  import org.apache.commons.math4.legacy.exception.NoDataException;
  import org.apache.commons.math4.legacy.exception.NullArgumentException;
  import org.apache.commons.math4.legacy.exception.NumberIsTooLargeException;
  import org.junit.Assert;
  import org.junit.Test;
  
  
  /**
   * Test cases for the WilcoxonSignedRangTest class.
   *
   */
  
  public class WilcoxonSignedRankTestTest {
  
      protected WilcoxonSignedRankTest testStatistic = new WilcoxonSignedRankTest();
  
      @Test
      public void testWilcoxonSignedRankSimple() {
          /* Target values computed using R version 2.11.1
           * x <- c(1.83, 0.50, 1.62, 2.48, 1.68, 1.88, 1.55, 3.06, 1.30)
           * y <- c(0.878, 0.647, 0.598, 2.05, 1.06, 1.29, 1.06, 3.14, 1.29)
           */
          final double x[] = {1.83, 0.50, 1.62, 2.48, 1.68, 1.88, 1.55, 3.06, 1.30};
          final double y[] = {0.878, 0.647, 0.598, 2.05, 1.06, 1.29, 1.06, 3.14, 1.29};
  
          /* EXACT:
           * wilcox.test(x, y, alternative = "two.sided", mu = 0, paired = TRUE, exact = TRUE, correct = FALSE)
           * V = 40, p-value = 0.03906
           *
           * Corresponds to the value obtained in R.
           */
          Assert.assertEquals(40, testStatistic.wilcoxonSignedRank(x, y), 1e-10);
          Assert.assertEquals(0.03906, testStatistic.wilcoxonSignedRankTest(x, y, true), 1e-5);
  
          /* ASYMPTOTIC:
           * wilcox.test(x, y, alternative = "two.sided", mu = 0, paired = TRUE, exact = FALSE, correct = FALSE)
           * V = 40, p-value = 0.03815
           *
           * This is not entirely the same due to different corrects,
           * e.g. http://mlsc.lboro.ac.uk/resources/statistics/wsrt.pdf
           * and src/library/stats/R/wilcox.test.R in the R source
           */
          Assert.assertEquals(40, testStatistic.wilcoxonSignedRank(x, y), 1e-10);
          Assert.assertEquals(0.0329693812, testStatistic.wilcoxonSignedRankTest(x, y, false), 1e-10);
      }
  
      @Test
      public void testWilcoxonSignedRankInputValidation() {
          /*
           * Exact only for sample size <= 30
           */
          final double[] x1 = new double[30];
          final double[] x2 = new double[31];
          final double[] y1 = new double[30];
          final double[] y2 = new double[31];
          for (int i = 0; i < 30; ++i) {
              x1[i] = x2[i] = y1[i] = y2[i] = i;
          }
  
          // Exactly 30 is okay
          //testStatistic.wilcoxonSignedRankTest(x1, y1, true);
  
          try {
              testStatistic.wilcoxonSignedRankTest(x2, y2, true);
              Assert.fail("More than 30 samples and exact chosen, NumberIsTooLargeException expected");
          } catch (NumberIsTooLargeException ex) {
              // expected
          }
  
          /* Samples must be present, i.e. length > 0
           */
          try {
              testStatistic.wilcoxonSignedRankTest(new double[] { }, new double[] { 1.0 }, true);
              Assert.fail("x does not contain samples (exact), NoDataException expected");
          } catch (NoDataException ex) {
              // expected
          }
  
          try {
              testStatistic.wilcoxonSignedRankTest(new double[] { }, new double[] { 1.0 }, false);
             Assert.fail("x does not contain samples (asymptotic), NoDataException expected");
         } catch (NoDataException ex) {
             // expected
         }
 
         try {
             testStatistic.wilcoxonSignedRankTest(new double[] { 1.0 }, new double[] { }, true);
             Assert.fail("y does not contain samples (exact), NoDataException expected");
         } catch (NoDataException ex) {
             // expected
         }
 
         try {
             testStatistic.wilcoxonSignedRankTest(new double[] { 1.0 }, new double[] { }, false);
             Assert.fail("y does not contain samples (asymptotic), NoDataException expected");
         } catch (NoDataException ex) {
             // expected
         }
 
         /* Samples not same size, i.e. cannot be paired
          */
         try {
             testStatistic.wilcoxonSignedRankTest(new double[] { 1.0, 2.0 }, new double[] { 3.0 }, true);
             Assert.fail("x and y not same size (exact), DimensionMismatchException expected");
         } catch (DimensionMismatchException ex) {
             // expected
         }
 
         try {
             testStatistic.wilcoxonSignedRankTest(new double[] { 1.0, 2.0 }, new double[] { 3.0 }, false);
             Assert.fail("x and y not same size (asymptotic), DimensionMismatchException expected");
         } catch (DimensionMismatchException ex) {
             // expected
         }
 
         /*
          * x and y is null
          */
         try {
             testStatistic.wilcoxonSignedRankTest(null, null, true);
             Assert.fail("x and y is null (exact), NullArgumentException expected");
         } catch (NullArgumentException ex) {
             // expected
         }
 
         try {
             testStatistic.wilcoxonSignedRankTest(null, null, false);
             Assert.fail("x and y is null (asymptotic), NullArgumentException expected");
         } catch (NullArgumentException ex) {
             // expected
         }
 
         /*
          * x or y is null
          */
         try {
             testStatistic.wilcoxonSignedRankTest(null, new double[] { 1.0 }, true);
             Assert.fail("x is null (exact), NullArgumentException expected");
         } catch (NullArgumentException ex) {
             // expected
         }
 
         try {
             testStatistic.wilcoxonSignedRankTest(null, new double[] { 1.0 }, false);
             Assert.fail("x is null (asymptotic), NullArgumentException expected");
         } catch (NullArgumentException ex) {
             // expected
         }
 
         try {
             testStatistic.wilcoxonSignedRankTest(new double[] { 1.0 }, null, true);
             Assert.fail("y is null (exact), NullArgumentException expected");
         } catch (NullArgumentException ex) {
             // expected
         }
 
         try {
             testStatistic.wilcoxonSignedRankTest(new double[] { 1.0 }, null, false);
             Assert.fail("y is null (asymptotic), NullArgumentException expected");
         } catch (NullArgumentException ex) {
             // expected
         }
     }
 }