Package org.apache.commons.math4.util

Class MathUtils

java.lang.Object
org.apache.commons.math4.util.MathUtils
public final class MathUtils
extends java.lang.Object
Miscellaneous utility functions.
See Also:
MathArrays

  • Field Summary

    Fields 
    Modifier and Type Field Description
    static double PI_SQUARED
    \(\pi^2\)
    static double TWO_PI
    \(2\pi\)

  • Method Summary

    Modifier and Type Method Description
    static void checkFinite​(double x)
    Check that the argument is a real number.
    static void checkFinite​(double[] val)
    Check that all the elements are real numbers.
    static void checkNotNull​(java.lang.Object o)
    Checks that an object is not null.
    static void checkNotNull​(java.lang.Object o, Localizable pattern, java.lang.Object... args)
    Checks that an object is not null.
    static byte copySign​(byte magnitude, byte sign)
    Returns the first argument with the sign of the second argument.
    static int copySign​(int magnitude, int sign)
    Returns the first argument with the sign of the second argument.
    static long copySign​(long magnitude, long sign)
    Returns the first argument with the sign of the second argument.
    static short copySign​(short magnitude, short sign)
    Returns the first argument with the sign of the second argument.
    static boolean equals​(double x, double y)
    Returns true if the values are equal according to semantics of Double.equals(Object).
    static int hash​(double value)
    Returns an integer hash code representing the given double value.
    static int hash​(double[] value)
    Returns an integer hash code representing the given double array.
    static <T extends RealFieldElement<T>>
    T    		 max​(T e1, T e2)
    Find the maximum of two field elements.
    static <T extends RealFieldElement<T>>
    T    		 min​(T e1, T e2)
    Find the minimum of two field elements.
    static double reduce​(double a, double period, double offset)
    Reduce |a - offset| to the primary interval [0, |period|).

    Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

  • Field Details

  • Method Details

    • hash

      public static int hash​(double value)
      Returns an integer hash code representing the given double value.
      Parameters:
      value - the value to be hashed
      Returns:
      the hash code

    • equals

      public static boolean equals​(double x, double y)
      Returns true if the values are equal according to semantics of Double.equals(Object).
      Parameters:
      x - Value
      y - Value
      Returns:
      new Double(x).equals(new Double(y))

    • hash

      public static int hash​(double[] value)
      Returns an integer hash code representing the given double array.
      Parameters:
      value - the value to be hashed (may be null)
      Returns:
      the hash code
      Since:
      1.2

    • max

      public static <T extends RealFieldElement<T>> T max​(T e1, T e2)
      Find the maximum of two field elements.
      Type Parameters:
      T - the type of the field elements
      Parameters:
      e1 - first element
      e2 - second element
      Returns:
      max(a1, e2)
      Since:
      3.6

    • min

      public static <T extends RealFieldElement<T>> T min​(T e1, T e2)
      Find the minimum of two field elements.
      Type Parameters:
      T - the type of the field elements
      Parameters:
      e1 - first element
      e2 - second element
      Returns:
      min(a1, e2)
      Since:
      3.6

    • reduce

      public static double reduce​(double a, double period, double offset)

      Reduce |a - offset| to the primary interval [0, |period|).

      Specifically, the value returned is
      a - |period| * floor((a - offset) / |period|) - offset.

      If any of the parameters are NaN or infinite, the result is NaN.

      Parameters:
      a - Value to reduce.
      period - Period.
      offset - Value that will be mapped to 0.
      Returns:
      the value, within the interval [0 |period|), that corresponds to a.

    • copySign

      public static byte copySign​(byte magnitude, byte sign) throws MathArithmeticException
      Returns the first argument with the sign of the second argument.
      Parameters:
      magnitude - Magnitude of the returned value.
      sign - Sign of the returned value.
      Returns:
      a value with magnitude equal to magnitude and with the same sign as the sign argument.
      Throws:
      MathArithmeticException - if magnitude == Byte.MIN_VALUE and sign >= 0.

    • copySign

      public static short copySign​(short magnitude, short sign) throws MathArithmeticException
      Returns the first argument with the sign of the second argument.
      Parameters:
      magnitude - Magnitude of the returned value.
      sign - Sign of the returned value.
      Returns:
      a value with magnitude equal to magnitude and with the same sign as the sign argument.
      Throws:
      MathArithmeticException - if magnitude == Short.MIN_VALUE and sign >= 0.

    • copySign

      public static int copySign​(int magnitude, int sign) throws MathArithmeticException
      Returns the first argument with the sign of the second argument.
      Parameters:
      magnitude - Magnitude of the returned value.
      sign - Sign of the returned value.
      Returns:
      a value with magnitude equal to magnitude and with the same sign as the sign argument.
      Throws:
      MathArithmeticException - if magnitude == Integer.MIN_VALUE and sign >= 0.

    • copySign

      public static long copySign​(long magnitude, long sign) throws MathArithmeticException
      Returns the first argument with the sign of the second argument.
      Parameters:
      magnitude - Magnitude of the returned value.
      sign - Sign of the returned value.
      Returns:
      a value with magnitude equal to magnitude and with the same sign as the sign argument.
      Throws:
      MathArithmeticException - if magnitude == Long.MIN_VALUE and sign >= 0.

    • checkFinite

      public static void checkFinite​(double x) throws NotFiniteNumberException
      Check that the argument is a real number.
      Parameters:
      x - Argument.
      Throws:
      NotFiniteNumberException - if x is not a finite real number.

    • checkFinite

      public static void checkFinite​(double[] val) throws NotFiniteNumberException
      Check that all the elements are real numbers.
      Parameters:
      val - Arguments.
      Throws:
      NotFiniteNumberException - if any values of the array is not a finite real number.

    • checkNotNull

      public static void checkNotNull​(java.lang.Object o, Localizable pattern, java.lang.Object... args) throws NullArgumentException
      Checks that an object is not null.
      Parameters:
      o - Object to be checked.
      pattern - Message pattern.
      args - Arguments to replace the placeholders in pattern.
      Throws:
      NullArgumentException - if o is null.

    • checkNotNull

      public static void checkNotNull​(java.lang.Object o) throws NullArgumentException
      Checks that an object is not null.
      Parameters:
      o - Object to be checked.
      Throws:
      NullArgumentException - if o is null.