org.apache.commons.math4.util

## Class MathUtils

• public final class MathUtils
extends Object
Miscellaneous utility functions.
MathArrays
• ### Field Summary

Fields
Modifier and Type Field and Description
static double PI_SQUARED
$$\pi^2$$
static double TWO_PI
$$2\pi$$
• ### Method Summary

All Methods
Modifier and Type Method and 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(Object o)
Checks that an object is not null.
static void checkNotNull(Object o, Localizable pattern, 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 Detail

• #### TWO_PI

public static final double TWO_PI
$$2\pi$$
Since:
2.1
Constant Field Values
• #### PI_SQUARED

public static final double PI_SQUARED
$$\pi^2$$
Since:
3.4
Constant Field Values
• ### Method Detail

• #### 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:
Double.valueOf(x).equals(Double.valueOf(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(Object o,
Localizable pattern,
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(Object o)
throws NullArgumentException
Checks that an object is not null.
Parameters:
o - Object to be checked.
Throws:
NullArgumentException - if o is null.