Method Detail

• assertDouble

  public static void assertDouble​(double d)
                           throws java.lang.IllegalArgumentException

  Asserts that the given double is not invalid for calculation.

  It must not be one of:

  • Double.NaN
  • Double.NEGATIVE_INFINITY
  • Double.POSITIVE_INFINITY

  Parameters:

  d - the double to test.

  Throws:

  java.lang.IllegalArgumentException - if the assertion fails.

• assertEqual

  public static boolean assertEqual​(double d1,
                                    double d2,
                                    double precisionRange)

  Asserts if the given two doubles are equal within the given precision range by the operation:

   Math.abs(d1 - d2) < precision
   

  .

  Because floating point calculations may involve rounding, calculated float and double values may not be accurate. This routine should be used instead. If called with a very small precision range this routine will not be stable against the rounding of calculated floats but at least prevent a bug report of the findbugs tool. See the Java Language Specification, section 4.2.4.

  Parameters:

  d1 - a double to check equality to the other given double.

  d2 - a double to check equality to the other given double.

  precisionRange - the range to allow differences of the two doubles without judging a difference - this is typically a small value below 0.5.

  Returns:

  true if both given doubles are equal within the given precision range.

• getInstance

  public static MathUtil getInstance​()

  Returns the singleton instance of this class.

  This method is useless for now as all methods are static. It may be used in future if VM-global configuration will be put to the state of the instance.

  #

  Returns:

  the singleton instance of this class.

• increment

  public static java.lang.Integer increment​(java.lang.Integer value)

  Raises the given integer by one (bad performance).

  Warning: Only use this for testing code or prototypes as a new instance might be created for each call. Use primitive data types when fast calculations are required.

  Warning: Never do the following: Integer count = new Integer(6); MathUtil.increment(count); // don't expect count now carries 6. Integers are immutable. Write: Integer count = new Integer(6); count = MathUtil.increment(count);

  Parameters:

  value - the value to increase, if null is used a new instance will be initialized with value 0 and incremented.

  Returns:

  a (potentially new by the means of Integer.valueOf(int)) value increased by one.

• isDouble

  public static boolean isDouble​(double d)

  Tests that the given double is not invalid for calculation.

  It must not be one of:

  • Double.NaN
  • Double.NEGATIVE_INFINITY
  • Double.POSITIVE_INFINITY

  Parameters:

  d - the double to test.

  Returns:

  true if the given double is valid for calculation (not infinite or NaN).