assertThat(ONE_VALUE_STATS.populationVariance()).isEqualTo(0.0);
    assertThat(Stats.of(POSITIVE_INFINITY).populationVariance()).isNaN();
    assertThat(Stats.of(NEGATIVE_INFINITY).populationVariance()).isNaN();
    assertThat(Stats.of(NaN).populationVariance()).isNaN();
    assertThat(TWO_VALUES_STATS.populationVariance())
        .isWithin(ALLOWED_ERROR)
        .of(TWO_VALUES_SUM_OF_SQUARES_OF_DELTAS / 2);

        assertWithMessage("mean of %s", values).that(mean).isNaN();
        assertWithMessage("mean by addAll(Stats) of %s", values).that(meanByAddAllStats).isNaN();
      } else if (values.hasAnyPositiveInfinity() && values.hasAnyNegativeInfinity()) {
        assertWithMessage("mean of %s", values).that(mean).isNaN();
        assertWithMessage("mean by addAll(Stats) of %s", values).that(meanByAddAllStats).isNaN();
      } else if (values.hasAnyPositiveInfinity()) {

        assertWithMessage("mean of %s", values).that(mean).isNaN();
        assertWithMessage("mean by addAll(Stats) of %s", values).that(meanByAddAllStats).isNaN();
      } else if (values.hasAnyPositiveInfinity() && values.hasAnyNegativeInfinity()) {
        assertWithMessage("mean of %s", values).that(mean).isNaN();
        assertWithMessage("mean by addAll(Stats) of %s", values).that(meanByAddAllStats).isNaN();
      } else if (values.hasAnyPositiveInfinity()) {

    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(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)

      if (values.hasAnyNonFinite()) {
        assertWithMessage("population covariance of %s", values).that(populationCovariance).isNaN();
        assertWithMessage("population covariance by addAll(PairedStats) of %s", values)
            .that(populationCovarianceByAddAllPartitionedPairedStats)
            .isNaN();
      } else {
        assertWithMessage("population covariance of %s", values)
            .that(populationCovariance)

import static java.lang.Double.MAX_EXPONENT;
import static java.lang.Double.MIN_EXPONENT;
import static java.lang.Double.POSITIVE_INFINITY;
import static java.lang.Double.doubleToRawLongBits;
import static java.lang.Double.isNaN;
import static java.lang.Double.longBitsToDouble;
import static java.lang.Math.getExponent;
import static java.lang.Math.max;

import com.google.common.annotations.GwtIncompatible;

    assertThat(transformation.isHorizontal()).isFalse();
    assertThat(transformation.isVertical()).isFalse();
    assertThat(transformation.slope()).isNaN();
    assertThat(transformation.transform(0.0)).isNaN();
    assertThat(transformation.inverse()).isSameInstanceAs(transformation);
  }

  /**
   * Creates a {@link PairedStats} from with the given lists of {@code x} and {@code y} values,

    assertThat(transformation.isHorizontal()).isFalse();
    assertThat(transformation.isVertical()).isFalse();
    assertThat(transformation.slope()).isNaN();
    assertThat(transformation.transform(0.0)).isNaN();
    assertThat(transformation.inverse()).isSameInstanceAs(transformation);
  }

  /**
   * Creates a {@link PairedStats} from with the given lists of {@code x} and {@code y} values,

      assertTrue(Double.isNaN(DoubleMath.log2(-d)));
    }
  }

  public void testLog2Zero() {
    assertThat(DoubleMath.log2(0.0)).isNegativeInfinity();
    assertThat(DoubleMath.log2(-0.0)).isNegativeInfinity();
  }

  public void testLog2NaNInfinity() {
    assertThat(DoubleMath.log2(Double.POSITIVE_INFINITY)).isPositiveInfinity();
    assertTrue(Double.isNaN(DoubleMath.log2(Double.NEGATIVE_INFINITY)));