java.lang.Object
- org.apache.commons.math4.core.jdkmath.AccurateMath

```
public final class AccurateMath
extends Object
```
Portable alternative to Math and StrictMath.
Caveat: At the time of implementation, the AccurateMath functions were often faster and/or more accurate than their JDK equivalent. Nowadays, it would not be surprising that they are always slower (due to the various JVM optimizations that have appeared since Java 5). However, any change to this class should ensure that the current accuracy is not lost.

AccurateMath speed is achieved by relying heavily on optimizing compilers to native code present in many JVMs today and use of large tables. The larger tables are lazily initialized on first use, so that the setup time does not penalize methods that don't need them.

Note that AccurateMath is extensively used inside Apache Commons Math, so by calling some algorithms, the overhead when the tables need to be initialized will occur regardless of the end-user calling AccurateMath methods directly or not. Performance figures for a specific JVM and hardware can be evaluated by running the AccurateMathTestPerformance tests in the test directory of the source distribution.

AccurateMath accuracy should be mostly independent of the JVM as it relies only on IEEE-754 basic operations and on embedded tables. Almost all operations are accurate to about 0.5 ulp throughout the domain range. This statement, of course is only a rough global observed behavior, it is not a guarantee for every double numbers input (see William Kahan's Table Maker's Dilemma).

AccurateMath implements the following methods not found in Math/StrictMath:
Since:

2.2

Field Summary

Fields
Modifier and Type	Field	Description
`static double`	`E`	Napier's constant e, base of the natural logarithm.
`static double`	`PI`	Archimede's constant PI, ratio of circle circumference to diameter.

Method Summary

All Methods Static Methods Concrete Methods
Modifier and Type	Method	Description
`static double`	`abs(double x)`	Absolute value.
`static float`	`abs(float x)`	Absolute value.
`static int`	`abs(int x)`	Absolute value.
`static long`	`abs(long x)`	Absolute value.
`static double`	`acos(double x)`	Compute the arc cosine of a number.
`static double`	`acosh(double a)`	Compute the inverse hyperbolic cosine of a number.
`static int`	`addExact(int a, int b)`	Add two numbers, detecting overflows.
`static long`	`addExact(long a, long b)`	Add two numbers, detecting overflows.
`static double`	`asin(double x)`	Compute the arc sine of a number.
`static double`	`asinh(double a)`	Compute the inverse hyperbolic sine of a number.
`static double`	`atan(double x)`	Arctangent function.
`static double`	`atan2(double y, double x)`	Two arguments arctangent function.
`static double`	`atanh(double a)`	Compute the inverse hyperbolic tangent of a number.
`static double`	`cbrt(double x)`	Compute the cubic root of a number.
`static double`	`ceil(double x)`	Get the smallest whole number larger than x.
`static double`	`copySign(double magnitude, double sign)`	Returns the first argument with the sign of the second argument.
`static float`	`copySign(float magnitude, float sign)`	Returns the first argument with the sign of the second argument.
`static double`	`cos(double x)`	Cosine function.
`static double`	`cosh(double x)`	Compute the hyperbolic cosine of a number.
`static int`	`decrementExact(int n)`	Decrement a number, detecting overflows.
`static long`	`decrementExact(long n)`	Decrement a number, detecting overflows.
`static double`	`exp(double x)`	Exponential function.
`static double`	`expm1(double x)`	Compute exp(x) - 1.
`static double`	`floor(double x)`	Get the largest whole number smaller than x.
`static int`	`floorDiv(int a, int b)`	Finds q such that a = q b + r with 0 <= r < b if b > 0 and b < r <= 0 if b < 0.
`static long`	`floorDiv(long a, long b)`	Finds q such that a = q b + r with 0 <= r < b if b > 0 and b < r <= 0 if b < 0.
`static int`	`floorMod(int a, int b)`	Finds r such that a = q b + r with 0 <= r < b if b > 0 and b < r <= 0 if b < 0.
`static long`	`floorMod(long a, long b)`	Finds r such that a = q b + r with 0 <= r < b if b > 0 and b < r <= 0 if b < 0.
`static int`	`getExponent(double d)`	Return the exponent of a double number, removing the bias.
`static int`	`getExponent(float f)`	Return the exponent of a float number, removing the bias.
`static double`	`hypot(double x, double y)`	Returns the hypotenuse of a triangle with sides `x` and `y` - sqrt(x² +y²) avoiding intermediate overflow or underflow.
`static double`	`IEEEremainder(double dividend, double divisor)`	Computes the remainder as prescribed by the IEEE 754 standard.
`static int`	`incrementExact(int n)`	Increment a number, detecting overflows.
`static long`	`incrementExact(long n)`	Increment a number, detecting overflows.
`static double`	`log(double x)`	Natural logarithm.
`static double`	`log(double base, double x)`	Computes the logarithm in a given base.
`static double`	`log10(double x)`	Compute the base 10 logarithm.
`static double`	`log1p(double x)`	Computes log(1 + x).
`static void`	`main(String[] a)`	Print out contents of arrays, and check the length.
`static double`	`max(double a, double b)`	Compute the maximum of two values.
`static float`	`max(float a, float b)`	Compute the maximum of two values.
`static int`	`max(int a, int b)`	Compute the maximum of two values.
`static long`	`max(long a, long b)`	Compute the maximum of two values.
`static double`	`min(double a, double b)`	Compute the minimum of two values.
`static float`	`min(float a, float b)`	Compute the minimum of two values.
`static int`	`min(int a, int b)`	Compute the minimum of two values.
`static long`	`min(long a, long b)`	Compute the minimum of two values.
`static int`	`multiplyExact(int a, int b)`	Multiply two numbers, detecting overflows.
`static long`	`multiplyExact(long a, long b)`	Multiply two numbers, detecting overflows.
`static double`	`nextAfter(double d, double direction)`	Get the next machine representable number after a number, moving in the direction of another number.
`static float`	`nextAfter(float f, double direction)`	Get the next machine representable number after a number, moving in the direction of another number.
`static double`	`nextDown(double a)`	Compute next number towards negative infinity.
`static float`	`nextDown(float a)`	Compute next number towards negative infinity.
`static double`	`nextUp(double a)`	Compute next number towards positive infinity.
`static float`	`nextUp(float a)`	Compute next number towards positive infinity.
`static double`	`pow(double x, double y)`	Power function.
`static double`	`pow(double d, int e)`	Raise a double to an int power.
`static double`	`pow(double d, long e)`	Raise a double to a long power.
`static double`	`rint(double x)`	Get the whole number that is the nearest to x, or the even one if x is exactly half way between two integers.
`static long`	`round(double x)`	Get the closest long to x.
`static int`	`round(float x)`	Get the closest int to x.
`static double`	`scalb(double d, int n)`	Multiply a double number by a power of 2.
`static float`	`scalb(float f, int n)`	Multiply a float number by a power of 2.
`static double`	`signum(double a)`	Compute the signum of a number.
`static float`	`signum(float a)`	Compute the signum of a number.
`static double`	`sin(double x)`	Sine function.
`static double`	`sinh(double x)`	Compute the hyperbolic sine of a number.
`static int`	`subtractExact(int a, int b)`	Subtract two numbers, detecting overflows.
`static long`	`subtractExact(long a, long b)`	Subtract two numbers, detecting overflows.
`static double`	`tan(double x)`	Tangent function.
`static double`	`tanh(double x)`	Compute the hyperbolic tangent of a number.
`static double`	`toDegrees(double x)`	Convert radians to degrees, with error of less than 0.5 ULP.
`static int`	`toIntExact(long n)`	Convert a long to integer, detecting overflows.
`static double`	`toRadians(double x)`	Convert degrees to radians, with error of less than 0.5 ULP.
`static double`	`ulp(double x)`	Compute least significant bit (Unit in Last Position) for a number.
`static float`	`ulp(float x)`	Compute least significant bit (Unit in Last Position) for a number.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
 - PI
```
public static final double PI
```
 Archimede's constant PI, ratio of circle circumference to diameter.
 
 See Also:
 
 Constant Field Values
 - E
```
public static final double E
```
 Napier's constant e, base of the natural logarithm.
 
 See Also:
 
 Constant Field Values
- Method Detail
 - cosh
```
public static double cosh(double x)
```
 Compute the hyperbolic cosine of a number.
 
 Parameters:
 
 x - number on which evaluation is done
 
 Returns:
 
 hyperbolic cosine of x
 - sinh
```
public static double sinh(double x)
```
 Compute the hyperbolic sine of a number.
 
 Parameters:
 
 x - number on which evaluation is done
 
 Returns:
 
 hyperbolic sine of x
 - tanh
```
public static double tanh(double x)
```
 Compute the hyperbolic tangent of a number.
 
 Parameters:
 
 x - number on which evaluation is done
 
 Returns:
 
 hyperbolic tangent of x
 - acosh
```
public static double acosh(double a)
```
 Compute the inverse hyperbolic cosine of a number.
 
 Parameters:
 
 a - number on which evaluation is done
 
 Returns:
 
 inverse hyperbolic cosine of a
 - asinh
```
public static double asinh(double a)
```
 Compute the inverse hyperbolic sine of a number.
 
 Parameters:
 
 a - number on which evaluation is done
 
 Returns:
 
 inverse hyperbolic sine of a
 - atanh
```
public static double atanh(double a)
```
 Compute the inverse hyperbolic tangent of a number.
 
 Parameters:
 
 a - number on which evaluation is done
 
 Returns:
 
 inverse hyperbolic tangent of a
 - signum
```
public static double signum(double a)
```
 Compute the signum of a number. The signum is -1 for negative numbers, +1 for positive numbers and 0 otherwise
 
 Parameters:
 
 a - number on which evaluation is done
 
 Returns:
 
 -1.0, -0.0, +0.0, +1.0 or NaN depending on sign of a
 - signum
```
public static float signum(float a)
```
 Compute the signum of a number. The signum is -1 for negative numbers, +1 for positive numbers and 0 otherwise
 
 Parameters:
 
 a - number on which evaluation is done
 
 Returns:
 
 -1.0, -0.0, +0.0, +1.0 or NaN depending on sign of a
 - nextUp
```
public static double nextUp(double a)
```
 Compute next number towards positive infinity.
 
 Parameters:
 
 a - number to which neighbor should be computed
 
 Returns:
 
 neighbor of a towards positive infinity
 - nextUp
```
public static float nextUp(float a)
```
 Compute next number towards positive infinity.
 
 Parameters:
 
 a - number to which neighbor should be computed
 
 Returns:
 
 neighbor of a towards positive infinity
 - nextDown
```
public static double nextDown(double a)
```
 Compute next number towards negative infinity.
 
 Parameters:
 
 a - number to which neighbor should be computed
 
 Returns:
 
 neighbor of a towards negative infinity
 
 Since:
 
 3.4
 - nextDown
```
public static float nextDown(float a)
```
 Compute next number towards negative infinity.
 
 Parameters:
 
 a - number to which neighbor should be computed
 
 Returns:
 
 neighbor of a towards negative infinity
 
 Since:
 
 3.4
 - exp
```
public static double exp(double x)
```
 Exponential function. Computes exp(x), function result is nearly rounded. It will be correctly rounded to the theoretical value for 99.9% of input values, otherwise it will have a 1 ULP error. Method: Lookup intVal = exp(int(x)) Lookup fracVal = exp(int(x-int(x) / 1024.0) * 1024.0 ); Compute z as the exponential of the remaining bits by a polynomial minus one exp(x) = intVal * fracVal * (1 + z) Accuracy: Calculation is done with 63 bits of precision, so result should be correctly rounded for 99.9% of input values, with less than 1 ULP error otherwise.
 
 Parameters:
 
 x - a double
 
 Returns:
 
 double e^x
 - expm1
```
public static double expm1(double x)
```
 Compute exp(x) - 1.
 
 Parameters:
 
 x - number to compute shifted exponential
 
 Returns:
 
 exp(x) - 1
 - log
```
public static double log(double x)
```
 Natural logarithm.
 
 Parameters:
 
 x - a double
 
 Returns:
 
 log(x)
 - log1p
```
public static double log1p(double x)
```
 Computes log(1 + x).
 
 Parameters:
 
 x - Number.
 
 Returns:
 
 log(1 + x).
 - log10
```
public static double log10(double x)
```
 Compute the base 10 logarithm.
 
 Parameters:
 
 x - a number
 
 Returns:
 
 log10(x)
 - log
```
public static double log(double base,
 double x)
```
 Computes the logarithm in a given base. Returns NaN if either argument is negative. If base is 0 and x is positive, 0 is returned. If base is positive and x is 0, Double.NEGATIVE_INFINITY is returned. If both arguments are 0, the result is NaN.
 
 Parameters:
 
 base - Base of the logarithm, must be greater than 0.
 
 x - Argument, must be greater than 0.
 
 Returns:
 
 the value of the logarithm, i.e. the number y such that base^y = x.
 
 Since:
 
 3.0
 - pow
```
public static double pow(double x,
 double y)
```
 Power function. Compute x^y.
 
 Parameters:
 
 x - a double
 
 y - a double
 
 Returns:
 
 double
 - pow
```
public static double pow(double d,
 int e)
```
 Raise a double to an int power.
 
 Parameters:
 
 d - Number to raise.
 
 e - Exponent.
 
 Returns:
 
 d^e
 
 Since:
 
 3.1
 - pow
```
public static double pow(double d,
 long e)
```
 Raise a double to a long power.
 
 Parameters:
 
 d - Number to raise.
 
 e - Exponent.
 
 Returns:
 
 d^e
 
 Since:
 
 3.6
 - sin
```
public static double sin(double x)
```
 Sine function.
 
 Parameters:
 
 x - Argument.
 
 Returns:
 
 sin(x)
 - cos
```
public static double cos(double x)
```
 Cosine function.
 
 Parameters:
 
 x - Argument.
 
 Returns:
 
 cos(x)
 - tan
```
public static double tan(double x)
```
 Tangent function.
 
 Parameters:
 
 x - Argument.
 
 Returns:
 
 tan(x)
 - atan
```
public static double atan(double x)
```
 Arctangent function.
 
 Parameters:
 
 x - a number
 
 Returns:
 
 atan(x)
 - atan2
```
public static double atan2(double y,
 double x)
```
 Two arguments arctangent function.
 
 Parameters:
 
 y - ordinate
 
 x - abscissa
 
 Returns:
 
 phase angle of point (x,y) between -PI and PI
 - asin
```
public static double asin(double x)
```
 Compute the arc sine of a number.
 
 Parameters:
 
 x - number on which evaluation is done
 
 Returns:
 
 arc sine of x
 - acos
```
public static double acos(double x)
```
 Compute the arc cosine of a number.
 
 Parameters:
 
 x - number on which evaluation is done
 
 Returns:
 
 arc cosine of x
 - cbrt
```
public static double cbrt(double x)
```
 Compute the cubic root of a number.
 
 Parameters:
 
 x - number on which evaluation is done
 
 Returns:
 
 cubic root of x
 - toRadians
```
public static double toRadians(double x)
```
 Convert degrees to radians, with error of less than 0.5 ULP.
 
 Parameters:
 
 x - angle in degrees
 
 Returns:
 
 x converted into radians
 - toDegrees
```
public static double toDegrees(double x)
```
 Convert radians to degrees, with error of less than 0.5 ULP.
 
 Parameters:
 
 x - angle in radians
 
 Returns:
 
 x converted into degrees
 - abs
```
public static int abs(int x)
```
 Absolute value.
 
 Parameters:
 
 x - number from which absolute value is requested
 
 Returns:
 
 abs(x)
 - abs
```
public static long abs(long x)
```
 Absolute value.
 
 Parameters:
 
 x - number from which absolute value is requested
 
 Returns:
 
 abs(x)
 - abs
```
public static float abs(float x)
```
 Absolute value.
 
 Parameters:
 
 x - number from which absolute value is requested
 
 Returns:
 
 abs(x)
 - abs
```
public static double abs(double x)
```
 Absolute value.
 
 Parameters:
 
 x - number from which absolute value is requested
 
 Returns:
 
 abs(x)
 - ulp
```
public static double ulp(double x)
```
 Compute least significant bit (Unit in Last Position) for a number.
 
 Parameters:
 
 x - number from which ulp is requested
 
 Returns:
 
 ulp(x)
 - ulp
```
public static float ulp(float x)
```
 Compute least significant bit (Unit in Last Position) for a number.
 
 Parameters:
 
 x - number from which ulp is requested
 
 Returns:
 
 ulp(x)
 - scalb
```
public static double scalb(double d,
 int n)
```
 Multiply a double number by a power of 2.
 
 Parameters:
 
 d - number to multiply
 
 n - power of 2
 
 Returns:
 
 d × 2ⁿ
 - scalb
```
public static float scalb(float f,
 int n)
```
 Multiply a float number by a power of 2.
 
 Parameters:
 
 f - number to multiply
 
 n - power of 2
 
 Returns:
 
 f × 2ⁿ
 - nextAfter
```
public static double nextAfter(double d,
 double direction)
```
 Get the next machine representable number after a number, moving in the direction of another number.
 The ordering is as follows (increasing):
 
 -INFINITY
 
 -MAX_VALUE
 
 -MIN_VALUE
 
 -0.0
 
 +0.0
 
 +MIN_VALUE
 
 +MAX_VALUE
 
 +INFINITY
 
 If arguments compare equal, then the second argument is returned.
 If direction is greater than d, the smallest machine representable number strictly greater than d is returned; if less, then the largest representable number strictly less than d is returned.
 
 If d is infinite and direction does not bring it back to finite numbers, it is returned unchanged.
 Parameters:
 
 d - base number
 
 direction - (the only important thing is whether direction is greater or smaller than d)
 
 Returns:
 
 the next machine representable number in the specified direction
 - nextAfter
```
public static float nextAfter(float f,
 double direction)
```
 Get the next machine representable number after a number, moving in the direction of another number.
 The ordering is as follows (increasing):
 
 -INFINITY
 
 -MAX_VALUE
 
 -MIN_VALUE
 
 -0.0
 
 +0.0
 
 +MIN_VALUE
 
 +MAX_VALUE
 
 +INFINITY
 
 If arguments compare equal, then the second argument is returned.
 If direction is greater than f, the smallest machine representable number strictly greater than f is returned; if less, then the largest representable number strictly less than f is returned.
 
 If f is infinite and direction does not bring it back to finite numbers, it is returned unchanged.
 Parameters:
 
 f - base number
 
 direction - (the only important thing is whether direction is greater or smaller than f)
 
 Returns:
 
 the next machine representable number in the specified direction
 - floor
```
public static double floor(double x)
```
 Get the largest whole number smaller than x.
 
 Parameters:
 
 x - number from which floor is requested
 
 Returns:
 
 a double number f such that f is an integer f <= x < f + 1.0
 - ceil
```
public static double ceil(double x)
```
 Get the smallest whole number larger than x.
 
 Parameters:
 
 x - number from which ceil is requested
 
 Returns:
 
 a double number c such that c is an integer c - 1.0 < x <= c
 - rint
```
public static double rint(double x)
```
 Get the whole number that is the nearest to x, or the even one if x is exactly half way between two integers.
 
 Parameters:
 
 x - number from which nearest whole number is requested
 
 Returns:
 
 a double number r such that r is an integer r - 0.5 <= x <= r + 0.5
 - round
```
public static long round(double x)
```
 Get the closest long to x.
 
 Parameters:
 
 x - number from which closest long is requested
 
 Returns:
 
 closest long to x
 - round
```
public static int round(float x)
```
 Get the closest int to x.
 
 Parameters:
 
 x - number from which closest int is requested
 
 Returns:
 
 closest int to x
 - min
```
public static int min(int a,
 int b)
```
 Compute the minimum of two values.
 
 Parameters:
 
 a - first value
 
 b - second value
 
 Returns:
 
 a if a is lesser or equal to b, b otherwise
 - min
```
public static long min(long a,
 long b)
```
 Compute the minimum of two values.
 
 Parameters:
 
 a - first value
 
 b - second value
 
 Returns:
 
 a if a is lesser or equal to b, b otherwise
 - min
```
public static float min(float a,
 float b)
```
 Compute the minimum of two values.
 
 Parameters:
 
 a - first value
 
 b - second value
 
 Returns:
 
 a if a is lesser or equal to b, b otherwise
 - min
```
public static double min(double a,
 double b)
```
 Compute the minimum of two values.
 
 Parameters:
 
 a - first value
 
 b - second value
 
 Returns:
 
 a if a is lesser or equal to b, b otherwise
 - max
```
public static int max(int a,
 int b)
```
 Compute the maximum of two values.
 
 Parameters:
 
 a - first value
 
 b - second value
 
 Returns:
 
 b if a is lesser or equal to b, a otherwise
 - max
```
public static long max(long a,
 long b)
```
 Compute the maximum of two values.
 
 Parameters:
 
 a - first value
 
 b - second value
 
 Returns:
 
 b if a is lesser or equal to b, a otherwise
 - max
```
public static float max(float a,
 float b)
```
 Compute the maximum of two values.
 
 Parameters:
 
 a - first value
 
 b - second value
 
 Returns:
 
 b if a is lesser or equal to b, a otherwise
 - max
```
public static double max(double a,
 double b)
```
 Compute the maximum of two values.
 
 Parameters:
 
 a - first value
 
 b - second value
 
 Returns:
 
 b if a is lesser or equal to b, a otherwise
 - hypot
```
public static double hypot(double x,
 double y)
```
 Returns the hypotenuse of a triangle with sides x and y - sqrt(x² +y²)
 avoiding intermediate overflow or underflow.
 
 If either argument is infinite, then the result is positive infinity.
 
 else, if either argument is NaN then the result is NaN.
 Parameters:
 
 x - a value
 
 y - a value
 
 Returns:
 
 sqrt(x² +y²)
 - IEEEremainder
```
public static double IEEEremainder(double dividend,
 double divisor)
```
 Computes the remainder as prescribed by the IEEE 754 standard. The remainder value is mathematically equal to x - y*n where n is the mathematical integer closest to the exact mathematical value of the quotient x/y. If two mathematical integers are equally close to x/y then n is the integer that is even.
 
 If either operand is NaN, the result is NaN.
 
 If the result is not NaN, the sign of the result equals the sign of the dividend.
 
 If the dividend is an infinity, or the divisor is a zero, or both, the result is NaN.
 
 If the dividend is finite and the divisor is an infinity, the result equals the dividend.
 
 If the dividend is a zero and the divisor is finite, the result equals the dividend.
 Parameters:
 
 dividend - the number to be divided
 
 divisor - the number by which to divide
 
 Returns:
 
 the remainder, rounded
 - toIntExact
```
public static int toIntExact(long n)
```
 Convert a long to integer, detecting overflows.
 
 Parameters:
 
 n - number to convert to int
 
 Returns:
 
 integer with same value as n if no overflows occur
 
 Throws:
 
 ArithmeticException - if n cannot fit into an int
 
 Since:
 
 3.4
 - incrementExact
```
public static int incrementExact(int n)
```
 Increment a number, detecting overflows.
 
 Parameters:
 
 n - number to increment
 
 Returns:
 
 n+1 if no overflows occur
 
 Throws:
 
 ArithmeticException - if an overflow occurs
 
 Since:
 
 3.4
 - incrementExact
```
public static long incrementExact(long n)
```
 Increment a number, detecting overflows.
 
 Parameters:
 
 n - number to increment
 
 Returns:
 
 n+1 if no overflows occur
 
 Throws:
 
 ArithmeticException - if an overflow occurs
 
 Since:
 
 3.4
 - decrementExact
```
public static int decrementExact(int n)
```
 Decrement a number, detecting overflows.
 
 Parameters:
 
 n - number to decrement
 
 Returns:
 
 n-1 if no overflows occur
 
 Throws:
 
 ArithmeticException - if an overflow occurs
 
 Since:
 
 3.4
 - decrementExact
```
public static long decrementExact(long n)
```
 Decrement a number, detecting overflows.
 
 Parameters:
 
 n - number to decrement
 
 Returns:
 
 n-1 if no overflows occur
 
 Throws:
 
 ArithmeticException - if an overflow occurs
 
 Since:
 
 3.4
 - addExact
```
public static int addExact(int a,
 int b)
```
 Add two numbers, detecting overflows.
 
 Parameters:
 
 a - first number to add
 
 b - second number to add
 
 Returns:
 
 a+b if no overflows occur
 
 Throws:
 
 ArithmeticException - if an overflow occurs
 
 Since:
 
 3.4
 - addExact
```
public static long addExact(long a,
 long b)
```
 Add two numbers, detecting overflows.
 
 Parameters:
 
 a - first number to add
 
 b - second number to add
 
 Returns:
 
 a+b if no overflows occur
 
 Throws:
 
 ArithmeticException - if an overflow occurs
 
 Since:
 
 3.4
 - subtractExact
```
public static int subtractExact(int a,
 int b)
```
 Subtract two numbers, detecting overflows.
 
 Parameters:
 
 a - first number
 
 b - second number to subtract from a
 
 Returns:
 
 a-b if no overflows occur
 
 Throws:
 
 ArithmeticException - if an overflow occurs
 
 Since:
 
 3.4
 - subtractExact
```
public static long subtractExact(long a,
 long b)
```
 Subtract two numbers, detecting overflows.
 
 Parameters:
 
 a - first number
 
 b - second number to subtract from a
 
 Returns:
 
 a-b if no overflows occur
 
 Throws:
 
 ArithmeticException - if an overflow occurs
 
 Since:
 
 3.4
 - multiplyExact
```
public static int multiplyExact(int a,
 int b)
```
 Multiply two numbers, detecting overflows.
 
 Parameters:
 
 a - first number to multiply
 
 b - second number to multiply
 
 Returns:
 
 a*b if no overflows occur
 
 Throws:
 
 ArithmeticException - if an overflow occurs
 
 Since:
 
 3.4
 - multiplyExact
```
public static long multiplyExact(long a,
 long b)
```
 Multiply two numbers, detecting overflows.
 
 Parameters:
 
 a - first number to multiply
 
 b - second number to multiply
 
 Returns:
 
 a*b if no overflows occur
 
 Throws:
 
 ArithmeticException - if an overflow occurs
 
 Since:
 
 3.4
 - floorDiv
```
public static int floorDiv(int a,
 int b)
```
 Finds q such that a = q b + r with 0 <= r 0 and b < r <= 0 if b < 0.
 This methods returns the same value as integer division when a and b are same signs, but returns a different value when they are opposite (i.e. q is negative).
 
 Parameters:
 
 a - dividend
 
 b - divisor
 
 Returns:
 
 q such that a = q b + r with 0 <= r 0 and b < r <= 0 if b < 0
 
 Throws:
 
 ArithmeticException - if b == 0
 
 Since:
 
 3.4
 
 See Also:
 
 floorMod(int, int)
 - floorDiv
```
public static long floorDiv(long a,
 long b)
```
 Finds q such that a = q b + r with 0 <= r 0 and b < r <= 0 if b < 0.
 This methods returns the same value as integer division when a and b are same signs, but returns a different value when they are opposite (i.e. q is negative).
 
 Parameters:
 
 a - dividend
 
 b - divisor
 
 Returns:
 
 q such that a = q b + r with 0 <= r 0 and b < r <= 0 if b < 0
 
 Throws:
 
 ArithmeticException - if b == 0
 
 Since:
 
 3.4
 
 See Also:
 
 floorMod(long, long)
 - floorMod
```
public static int floorMod(int a,
 int b)
```
 Finds r such that a = q b + r with 0 <= r 0 and b < r <= 0 if b < 0.
 This methods returns the same value as integer modulo when a and b are same signs, but returns a different value when they are opposite (i.e. q is negative).
 
 Parameters:
 
 a - dividend
 
 b - divisor
 
 Returns:
 
 r such that a = q b + r with 0 <= r 0 and b < r <= 0 if b < 0
 
 Throws:
 
 ArithmeticException - if b == 0
 
 Since:
 
 3.4
 
 See Also:
 
 floorDiv(int, int)
 - floorMod
```
public static long floorMod(long a,
 long b)
```
 Finds r such that a = q b + r with 0 <= r 0 and b < r <= 0 if b < 0.
 This methods returns the same value as integer modulo when a and b are same signs, but returns a different value when they are opposite (i.e. q is negative).
 
 Parameters:
 
 a - dividend
 
 b - divisor
 
 Returns:
 
 r such that a = q b + r with 0 <= r 0 and b < r <= 0 if b < 0
 
 Throws:
 
 ArithmeticException - if b == 0
 
 Since:
 
 3.4
 
 See Also:
 
 floorDiv(long, long)
 - copySign
```
public static double copySign(double magnitude,
 double sign)
```
 Returns the first argument with the sign of the second argument. A NaN sign argument is treated as positive.
 
 Parameters:
 
 magnitude - the value to return
 
 sign - the sign for the returned value
 
 Returns:
 
 the magnitude with the same sign as the sign argument
 - copySign
```
public static float copySign(float magnitude,
 float sign)
```
 Returns the first argument with the sign of the second argument. A NaN sign argument is treated as positive.
 
 Parameters:
 
 magnitude - the value to return
 
 sign - the sign for the returned value
 
 Returns:
 
 the magnitude with the same sign as the sign argument
 - getExponent
```
public static int getExponent(double d)
```
 Return the exponent of a double number, removing the bias.
 For double numbers of the form 2^x, the unbiased exponent is exactly x.
 
 Parameters:
 
 d - number from which exponent is requested
 
 Returns:
 
 exponent for d in IEEE754 representation, without bias
 - getExponent
```
public static int getExponent(float f)
```
 Return the exponent of a float number, removing the bias.
 For float numbers of the form 2^x, the unbiased exponent is exactly x.
 
 Parameters:
 
 f - number from which exponent is requested
 
 Returns:
 
 exponent for d in IEEE754 representation, without bias
 - main
```
public static void main(String[] a)
```
 Print out contents of arrays, and check the length.
 used to generate the preset arrays originally.
 
 Parameters:
 
 a - unused

Class AccurateMath

Field Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

PI

E

Method Detail

cosh

sinh

tanh

acosh

asinh

atanh

signum

signum

nextUp

nextUp

nextDown

nextDown

exp

expm1

log

log1p

log10

log

pow

pow

pow

sin

cos

tan

atan

atan2

asin

acos

cbrt

toRadians

toDegrees

abs

abs

abs

abs

ulp

ulp

scalb

scalb

nextAfter

nextAfter

floor

ceil

rint

round

round

min

min

min

min

max

max

max

max

hypot

IEEEremainder

toIntExact

incrementExact

incrementExact

decrementExact

decrementExact

addExact

addExact

subtractExact

subtractExact

multiplyExact

multiplyExact

floorDiv

floorDiv

floorMod

floorMod

copySign