private static final double[] VALUES = {
    Double.NEGATIVE_INFINITY,
    -Double.MAX_VALUE,
    (double) Long.MIN_VALUE,
    (double) Integer.MIN_VALUE,
    -Math.PI,
    -1.0,
    -Double.MIN_VALUE,
    -0.0,
    +0.0,
    Double.MIN_VALUE,
    1.0,
    Math.PI,
    (double) Integer.MAX_VALUE,
    (double) Long.MAX_VALUE,
    Double.MAX_VALUE,
    Double.POSITIVE_INFINITY,

   */
  public static boolean fuzzyEquals(double a, double b, double tolerance) {
    MathPreconditions.checkNonNegative("tolerance", tolerance);
    return Math.copySign(a - b, 1.0) <= tolerance
        // copySign(x, 1.0) is a branch-free version of abs(x), but with different NaN semantics
        || (a == b) // needed to ensure that infinities equal themselves
        || (Double.isNaN(a) && Double.isNaN(b));
  }

  /**

 * Double#doubleToRawLongBits}, which differs from both the primitive double {@code ==} operator and
 * from {@link Double#equals}, as if implemented by:
 *
 * {@snippet :
 * static boolean bitEquals(double x, double y) {
 *   long xBits = Double.doubleToRawLongBits(x);
 *   long yBits = Double.doubleToRawLongBits(y);
 *   return xBits == yBits;
 * }
 * }
 *
 * @author Doug Lea
 * @author Martin Buchholz
 * @since 11.0
 */

        .setExpectation(Double.POSITIVE_INFINITY, UP, CEILING)
        .roundUnnecessaryShouldThrow()
        .test();
  }

  public void testRoundToDouble_wayTooBig() {
    BigDecimal bi = BigDecimal.valueOf(2).pow(2 * Double.MAX_EXPONENT);
    new RoundToDoubleTester(bi)
        .setExpectation(Double.MAX_VALUE, DOWN, FLOOR, HALF_EVEN, HALF_UP, HALF_DOWN)

    SIMPLE {
      @Override
      double mean(double[] values) {
        double sum = 0.0;
        for (double value : values) {
          sum += value;
        }
        return sum / values.length;
      }
    },
    KAHAN {
      @Override
      double mean(double[] values) {
        double sum = 0.0;
        double c = 0.0;
        for (double value : values) {
          double y = value - c;

    SIMPLE {
      @Override
      double mean(double[] values) {
        double sum = 0.0;
        for (double value : values) {
          sum += value;
        }
        return sum / values.length;
      }
    },
    KAHAN {
      @Override
      double mean(double[] values) {
        double sum = 0.0;
        double c = 0.0;
        for (double value : values) {
          double y = value - c;

  private static final double[] VALUES = {
    Double.NEGATIVE_INFINITY,
    -Double.MAX_VALUE,
    (double) Long.MIN_VALUE,
    (double) Integer.MIN_VALUE,
    -Math.PI,
    -1.0,
    -Double.MIN_VALUE,
    -0.0,
    +0.0,
    Double.MIN_VALUE,
    1.0,
    Math.PI,
    (double) Integer.MAX_VALUE,
    (double) Long.MAX_VALUE,
    Double.MAX_VALUE,
    Double.POSITIVE_INFINITY,

    assertTrue(Double.isNaN(DoubleMath.log2(Double.NaN)));
  }

  @GwtIncompatible // StrictMath
  @SuppressWarnings("strictfp") // Guava still supports Java 8
  private strictfp double trueLog2(double d) {
    double trueLog2 = StrictMath.log(d) / StrictMath.log(2);
    // increment until it's >= the true value
    while (StrictMath.pow(2.0, trueLog2) < d) {

  public void testRotate() {
    testRotate(new double[] {}, -1, new double[] {});
    testRotate(new double[] {}, 0, new double[] {});
    testRotate(new double[] {}, 1, new double[] {});

    testRotate(new double[] {1}, -2, new double[] {1});
    testRotate(new double[] {1}, -1, new double[] {1});
    testRotate(new double[] {1}, 0, new double[] {1});
    testRotate(new double[] {1}, 1, new double[] {1});

      Double[] suffix = {86.0, 99.0};
      Double[] all = concat(concat(prefix, elements), suffix);
      return makeArray(all).subArray(2, elements.length + 2).asList();
    }
  }

  @J2ktIncompatible
  @GwtIncompatible // used only from suite
  @AndroidIncompatible
  private static Double[] concat(Double[] a, Double[] b) {
    return ObjectArrays.concat(a, b, Double.class);
  }