.containsExactly(
            0, NEGATIVE_INFINITY,
            1, NEGATIVE_INFINITY, // interpolating between NEGATIVE_INFINITY and 1.0
            2, 1.0,
            8, 4.0,
            9, 4.5,
            10, 5.0);
  }

  public void testScale_index_compute_doubleCollection_negativeInfinity() {
    // interpolating between NEGATIVE_INFINITY and 1.0

        .containsExactly(
            0, NEGATIVE_INFINITY,
            1, NEGATIVE_INFINITY, // interpolating between NEGATIVE_INFINITY and 1.0
            2, 1.0,
            8, 4.0,
            9, 4.5,
            10, 5.0);
  }

  public void testScale_index_compute_doubleCollection_negativeInfinity() {
    // interpolating between NEGATIVE_INFINITY and 1.0

  private static final double[] EMPTY = {};
  private static final double[] ARRAY1 = {1.0};
  private static final double[] ARRAY234 = {2.0, 3.0, 4.0};

  private static final double LEAST = Double.NEGATIVE_INFINITY;
  private static final double GREATEST = Double.POSITIVE_INFINITY;

  private static final double[] NUMBERS =
      new double[] {
        LEAST,
        -Double.MAX_VALUE,
        -1.0,
        -0.5,

    assertThat(ONE_VALUE_PAIRED_STATS.populationCovariance()).isEqualTo(0.0);
    assertThat(createSingleStats(Double.POSITIVE_INFINITY, 1.23).populationCovariance()).isNaN();
    assertThat(createSingleStats(Double.NEGATIVE_INFINITY, 1.23).populationCovariance()).isNaN();
    assertThat(createSingleStats(Double.NaN, 1.23).populationCovariance()).isNaN();
    assertThat(TWO_VALUES_PAIRED_STATS.populationCovariance())
        .isWithin(ALLOWED_ERROR)

    assertThat(ONE_VALUE_PAIRED_STATS.populationCovariance()).isEqualTo(0.0);
    assertThat(createSingleStats(Double.POSITIVE_INFINITY, 1.23).populationCovariance()).isNaN();
    assertThat(createSingleStats(Double.NEGATIVE_INFINITY, 1.23).populationCovariance()).isNaN();
    assertThat(createSingleStats(Double.NaN, 1.23).populationCovariance()).isNaN();
    assertThat(TWO_VALUES_PAIRED_STATS.populationCovariance())
        .isWithin(ALLOWED_ERROR)