StrictMath (Java Platform SE 6)

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java.lang
class StrictMath

java.lang.Object
  java.lang.StrictMath

public final class StrictMath
extends Object

The class StrictMath contains methods for performing basic numeric operations such as the elementary exponential, logarithm, square root, and trigonometric functions.

To help ensure portability of Java programs, the definitions of some of the numeric functions in this package require that they produce the same results as certain published algorithms. These algorithms are available from the well-known network library netlib as the package "Freely Distributable Math Library," fdlibm. These algorithms, which are written in the C programming language, are then to be understood as executed with all floating-point operations following the rules of Java floating-point arithmetic.

The Java math library is defined with respect to fdlibm version 5.3. Where fdlibm provides more than one definition for a function (such as acos), use the "IEEE 754 core function" version (residing in a file whose name begins with the letter e). The methods which require fdlibm semantics are sin, cos, tan, asin, acos, atan, exp, log, log10, cbrt, atan2, pow, sinh, cosh, tanh, hypot, expm1, and log1p.

Field Summary
`static double`	`E` The `double` value that is closer than any other to e, the base of the natural logarithms.
`static double`	`PI` The `double` value that is closer than any other to pi, the ratio of the circumference of a circle to its diameter.

Method Summary
`static double`	`abs(double a)` Returns the absolute value of a `double` value.
`static float`	`abs(float a)` Returns the absolute value of a `float` value.
`static int`	`abs(int a)` Returns the absolute value of an `int` value..
`static long`	`abs(long a)` Returns the absolute value of a `long` value.
`static native double`	`acos(double a)` Returns the arc cosine of a value; the returned angle is in the range 0.0 through pi.
`static native double`	`asin(double a)` Returns the arc sine of a value; the returned angle is in the range -pi/2 through pi/2.
`static native double`	`atan(double a)` Returns the arc tangent of a value; the returned angle is in the range -pi/2 through pi/2.
`static native double`	`atan2(double y, double x)` Returns the angle theta from the conversion of rectangular coordinates (`x`, `y`) to polar coordinates (r, theta).
`static native double`	`cbrt(double a)` Returns the cube root of a `double` value.
`static native double`	`ceil(double a)` Returns the smallest (closest to negative infinity) `double` value that is greater than or equal to the argument and is equal to a mathematical integer.
`static double`	`copySign(double magnitude, double sign)` Returns the first floating-point argument with the sign of the second floating-point argument.
`static float`	`copySign(float magnitude, float sign)` Returns the first floating-point argument with the sign of the second floating-point argument.
`static native double`	`cos(double a)` Returns the trigonometric cosine of an angle.
`static native double`	`cosh(double x)` Returns the hyperbolic cosine of a `double` value.
`static native double`	`exp(double a)` Returns Euler's number e raised to the power of a `double` value.
`static native double`	`expm1(double x)` Returns e^x -1.
`static native double`	`floor(double a)` Returns the largest (closest to positive infinity) `double` value that is less than or equal to the argument and is equal to a mathematical integer.
`static int`	`getExponent(double d)` Returns the unbiased exponent used in the representation of a .
`static int`	`getExponent(float f)` Returns the unbiased exponent used in the representation of a .
`static native double`	`hypot(double x, double y)` Returns sqrt(x² +y²) without intermediate overflow or underflow.
`static native double`	`IEEEremainder(double f1, double f2)` Computes the remainder operation on two arguments as prescribed by the IEEE 754 standard.
`static native double`	`log(double a)` Returns the natural logarithm (base e) of a `double` value.
`static native double`	`log10(double a)` Returns the base 10 logarithm of a `double` value.
`static native double`	`log1p(double x)` Returns the natural logarithm of the sum of the argument and 1.
`static double`	`max(double a, double b)` Returns the greater of two `double` values.
`static float`	`max(float a, float b)` Returns the greater of two `float` values.
`static int`	`max(int a, int b)` Returns the greater of two `int` values.
`static long`	`max(long a, long b)` Returns the greater of two `long` values.
`static double`	`min(double a, double b)` Returns the smaller of two `double` values.
`static float`	`min(float a, float b)` Returns the smaller of two `float` values.
`static int`	`min(int a, int b)` Returns the smaller of two `int` values.
`static long`	`min(long a, long b)` Returns the smaller of two `long` values.
`static double`	`nextAfter(double start, double direction)` Returns the floating-point number adjacent to the first argument in the direction of the second argument.
`static float`	`nextAfter(float start, double direction)` Returns the floating-point number adjacent to the first argument in the direction of the second argument.
`static double`	`nextUp(double d)` Returns the floating-point value adjacent to in the direction of positive infinity.
`static float`	`nextUp(float f)` Returns the floating-point value adjacent to in the direction of positive infinity.
`static native double`	`pow(double a, double b)` Returns the value of the first argument raised to the power of the second argument.
`static double`	`random()` Returns a `double` value with a positive sign, greater than or equal to `0.0` and less than `1.0`.
`static double`	`rint(double a)` Returns the `double` value that is closest in value to the argument and is equal to a mathematical integer.
`static long`	`round(double a)` Returns the closest `long` to the argument.
`static int`	`round(float a)` Returns the closest `int` to the argument.
`static double`	`scalb(double d, int scaleFactor)` Return × 2 rounded as if performed by a single correctly rounded floating-point multiply to a member of the double value set.
`static float`	`scalb(float f, int scaleFactor)` Return × 2 rounded as if performed by a single correctly rounded floating-point multiply to a member of the float value set.
`static double`	`signum(double d)` Returns the signum function of the argument; zero if the argument is zero, 1.0 if the argument is greater than zero, -1.0 if the argument is less than zero.
`static float`	`signum(float f)` Returns the signum function of the argument; zero if the argument is zero, 1.0f if the argument is greater than zero, -1.0f if the argument is less than zero.
`static native double`	`sin(double a)` Returns the trigonometric sine of an angle.
`static native double`	`sinh(double x)` Returns the hyperbolic sine of a `double` value.
`static native double`	`sqrt(double a)` Returns the correctly rounded positive square root of a `double` value.
`static native double`	`tan(double a)` Returns the trigonometric tangent of an angle.
`static native double`	`tanh(double x)` Returns the hyperbolic tangent of a `double` value.
`static double`	`toDegrees(double angrad)` Converts an angle measured in radians to an approximately equivalent angle measured in degrees.
`static double`	`toRadians(double angdeg)` Converts an angle measured in degrees to an approximately equivalent angle measured in radians.
`static double`	`ulp(double d)` Returns the size of an ulp of the argument.
`static float`	`ulp(float f)` Returns the size of an ulp of the argument.

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

Field Detail

E

public static final double E

The double value that is closer than any other to e, the base of the natural logarithms.

PI

public static final double PI

The double value that is closer than any other to pi, the ratio of the circumference of a circle to its diameter.

Method Detail

abs

public static double abs(double a)

Returns the absolute value of a double value. If the argument is not negative, the argument is returned. If the argument is negative, the negation of the argument is returned. Special cases:

If the argument is positive zero or negative zero, the result is positive zero.
If the argument is infinite, the result is positive infinity.
If the argument is NaN, the result is NaN.

In other words, the result is the same as the value of the expression:

Double.longBitsToDouble((Double.doubleToLongBits(a)<<1)>>>1)

Parameters:: a - the argument whose absolute value is to be determined
Returns:: the absolute value of the argument.

abs

public static float abs(float a)

Returns the absolute value of a float value. If the argument is not negative, the argument is returned. If the argument is negative, the negation of the argument is returned. Special cases:

If the argument is positive zero or negative zero, the result is positive zero.
If the argument is infinite, the result is positive infinity.
If the argument is NaN, the result is NaN.

In other words, the result is the same as the value of the expression:

Float.intBitsToFloat(0x7fffffff & Float.floatToIntBits(a))

Parameters:: a - the argument whose absolute value is to be determined
Returns:: the absolute value of the argument.

abs

public static int abs(int a)

Returns the absolute value of an int value.. If the argument is not negative, the argument is returned. If the argument is negative, the negation of the argument is returned.

Note that if the argument is equal to the value of Integer.MIN_VALUE, the most negative representable int value, the result is that same value, which is negative.

Parameters:: a - the argument whose absolute value is to be determined.
Returns:: the absolute value of the argument.

abs

public static long abs(long a)

Returns the absolute value of a long value. If the argument is not negative, the argument is returned. If the argument is negative, the negation of the argument is returned.

Note that if the argument is equal to the value of Long.MIN_VALUE, the most negative representable long value, the result is that same value, which is negative.

Parameters:: a - the argument whose absolute value is to be determined.
Returns:: the absolute value of the argument.

acos

public static native double acos(double a)

Returns the arc cosine of a value; the returned angle is in the range 0.0 through pi. Special case:

If the argument is NaN or its absolute value is greater than 1, then the result is NaN.

Parameters:: a - the value whose arc cosine is to be returned.
Returns:: the arc cosine of the argument.

asin

public static native double asin(double a)

Returns the arc sine of a value; the returned angle is in the range -pi/2 through pi/2. Special cases:

If the argument is NaN or its absolute value is greater than 1, then the result is NaN.
If the argument is zero, then the result is a zero with the same sign as the argument.

Parameters:: a - the value whose arc sine is to be returned.
Returns:: the arc sine of the argument.

atan

public static native double atan(double a)

Returns the arc tangent of a value; the returned angle is in the range -pi/2 through pi/2. Special cases:

If the argument is NaN, then the result is NaN.
If the argument is zero, then the result is a zero with the same sign as the argument.

Parameters:: a - the value whose arc tangent is to be returned.
Returns:: the arc tangent of the argument.

atan2

public static native double atan2(double y,
                                  double x)

Returns the angle theta from the conversion of rectangular coordinates (x, y) to polar coordinates (r, theta). This method computes the phase theta by computing an arc tangent of y/x in the range of -pi to pi. Special cases:

If either argument is NaN, then the result is NaN.
If the first argument is positive zero and the second argument is positive, or the first argument is positive and finite and the second argument is positive infinity, then the result is positive zero.
If the first argument is negative zero and the second argument is positive, or the first argument is negative and finite and the second argument is positive infinity, then the result is negative zero.
If the first argument is positive zero and the second argument is negative, or the first argument is positive and finite and the second argument is negative infinity, then the result is the double value closest to pi.
If the first argument is negative zero and the second argument is negative, or the first argument is negative and finite and the second argument is negative infinity, then the result is the double value closest to -pi.
If the first argument is positive and the second argument is positive zero or negative zero, or the first argument is positive infinity and the second argument is finite, then the result is the double value closest to pi/2.
If the first argument is negative and the second argument is positive zero or negative zero, or the first argument is negative infinity and the second argument is finite, then the result is the double value closest to -pi/2.
If both arguments are positive infinity, then the result is the double value closest to pi/4.
If the first argument is positive infinity and the second argument is negative infinity, then the result is the double value closest to 3*pi/4.
If the first argument is negative infinity and the second argument is positive infinity, then the result is the double value closest to -pi/4.
If both arguments are negative infinity, then the result is the double value closest to -3*pi/4.

Parameters:: y - the ordinate coordinate; x - the abscissa coordinate
Returns:: the theta component of the point (r, theta) in polar coordinates that corresponds to the point (x, y) in Cartesian coordinates.

cbrt

public static native double cbrt(double a)

Returns the cube root of a double value. For positive finite x,

cbrt(-x) ==
 -cbrt(x)

; that is, the cube root of a negative value is the negative of the cube root of that value's magnitude. Special cases:

If the argument is NaN, then the result is NaN.
If the argument is infinite, then the result is an infinity with the same sign as the argument.
If the argument is zero, then the result is a zero with the same sign as the argument.

Parameters:: a - a value.
Returns:: the cube root of a.

ceil

public static native double ceil(double a)

Returns the smallest (closest to negative infinity) double value that is greater than or equal to the argument and is equal to a mathematical integer. Special cases:

If the argument value is already equal to a mathematical integer, then the result is the same as the argument.
If the argument is NaN or an infinity or positive zero or negative zero, then the result is the same as the argument.
If the argument value is less than zero but greater than -1.0, then the result is negative zero.

Note that the value of StrictMath.ceil(x) is exactly the value of -StrictMath.floor(-x).

Parameters:: a - a value.
Returns:: the smallest (closest to negative infinity) floating-point value that is greater than or equal to the argument and is equal to a mathematical integer.

copySign

public static double copySign(double magnitude,
                              double sign)

Returns the first floating-point argument with the sign of the second floating-point argument. For this method, a NaN {@code sign} argument is always treated as if it were positive.

Parameters:: magnitude - the parameter providing the magnitude of the result; sign - the parameter providing the sign of the result
Returns:: a value with the magnitude of {@code magnitude} and the sign of {@code sign}.

copySign

public static float copySign(float magnitude,
                             float sign)

Returns the first floating-point argument with the sign of the second floating-point argument. For this method, a NaN {@code sign} argument is always treated as if it were positive.

Parameters:: magnitude - the parameter providing the magnitude of the result; sign - the parameter providing the sign of the result
Returns:: a value with the magnitude of {@code magnitude} and the sign of {@code sign}.

cos

public static native double cos(double a)

Returns the trigonometric cosine of an angle. Special cases:

If the argument is NaN or an infinity, then the result is NaN.

Parameters:: a - an angle, in radians.
Returns:: the cosine of the argument.

cosh

public static native double cosh(double x)

Returns the hyperbolic cosine of a double value. The hyperbolic cosine of x is defined to be (e^x + e^-x)/2 where e is {@linkplain Math#E Euler's number}.

Special cases:

If the argument is NaN, then the result is NaN.
If the argument is infinite, then the result is positive infinity.
If the argument is zero, then the result is 1.0.

Parameters:: x - The number whose hyperbolic cosine is to be returned.
Returns:: The hyperbolic cosine of x.

exp

public static native double exp(double a)

Returns Euler's number e raised to the power of a double value. Special cases:

If the argument is NaN, the result is NaN.
If the argument is positive infinity, then the result is positive infinity.
If the argument is negative infinity, then the result is positive zero.

Parameters:: a - the exponent to raise e to.
Returns:: the value e^a, where e is the base of the natural logarithms.

expm1

public static native double expm1(double x)

Returns e^x -1. Note that for values of x near 0, the exact sum of expm1(x) + 1 is much closer to the true result of e^x than exp(x).

Special cases:

If the argument is NaN, the result is NaN.
If the argument is positive infinity, then the result is positive infinity.
If the argument is negative infinity, then the result is -1.0.
If the argument is zero, then the result is a zero with the same sign as the argument.

Parameters:: x - the exponent to raise e to in the computation of e^x -1.
Returns:: the value e^x - 1.

floor

public static native double floor(double a)

Returns the largest (closest to positive infinity) double value that is less than or equal to the argument and is equal to a mathematical integer. Special cases:

If the argument value is already equal to a mathematical integer, then the result is the same as the argument.
If the argument is NaN or an infinity or positive zero or negative zero, then the result is the same as the argument.

Parameters:: a - a value.
Returns:: the largest (closest to positive infinity) floating-point value that less than or equal to the argument and is equal to a mathematical integer.

getExponent

public static int getExponent(double d)

Returns the unbiased exponent used in the representation of a {@code double}. Special cases:

If the argument is NaN or infinite, then the result is {@link Double#MAX_EXPONENT} + 1.
If the argument is zero or subnormal, then the result is {@link Double#MIN_EXPONENT} -1.

Parameters:: d - a {@code double} value

getExponent

public static int getExponent(float f)

Returns the unbiased exponent used in the representation of a {@code float}. Special cases:

If the argument is NaN or infinite, then the result is {@link Float#MAX_EXPONENT} + 1.
If the argument is zero or subnormal, then the result is {@link Float#MIN_EXPONENT} -1.

Parameters:: f - a {@code float} value

hypot

public static native double hypot(double x,
                                  double y)

Returns sqrt(x² +y²) without intermediate overflow or underflow.

Special cases:

If either argument is infinite, then the result is positive infinity.
If either argument is NaN and neither argument is infinite, then the result is NaN.

Parameters:: x - a value; y - a value
Returns:: sqrt(x² +y²) without intermediate overflow or underflow

IEEEremainder

public static native double IEEEremainder(double f1,
                                          double f2)

Computes the remainder operation on two arguments as prescribed by the IEEE 754 standard. The remainder value is mathematically equal to f1 - f2 × n, where n is the mathematical integer closest to the exact mathematical value of the quotient f1/f2, and if two mathematical integers are equally close to f1/f2, then n is the integer that is even. If the remainder is zero, its sign is the same as the sign of the first argument. Special cases:

If either argument is NaN, or the first argument is infinite, or the second argument is positive zero or negative zero, then the result is NaN.
If the first argument is finite and the second argument is infinite, then the result is the same as the first argument.

Parameters:: f1 - the dividend.; f2 - the divisor.
Returns:: the remainder when f1 is divided by f2.

log

public static native double log(double a)

Returns the natural logarithm (base e) of a double value. Special cases:

If the argument is NaN or less than zero, then the result is NaN.
If the argument is positive infinity, then the result is positive infinity.
If the argument is positive zero or negative zero, then the result is negative infinity.

Parameters:: a - a value
Returns:: the value ln a, the natural logarithm of a.

log10

public static native double log10(double a)

Returns the base 10 logarithm of a double value. Special cases:

If the argument is NaN or less than zero, then the result is NaN.
If the argument is positive infinity, then the result is positive infinity.
If the argument is positive zero or negative zero, then the result is negative infinity.
If the argument is equal to 10ⁿ for integer n, then the result is n.

Parameters:: a - a value
Returns:: the base 10 logarithm of a.

log1p

public static native double log1p(double x)

Returns the natural logarithm of the sum of the argument and 1. Note that for small values x, the result of log1p(x) is much closer to the true result of ln(1 + x) than the floating-point evaluation of log(1.0+x).

Special cases:

If the argument is NaN or less than -1, then the result is NaN.
If the argument is positive infinity, then the result is positive infinity.
If the argument is negative one, then the result is negative infinity.
If the argument is zero, then the result is a zero with the same sign as the argument.

Parameters:: x - a value
Returns:: the value ln(x + 1), the natural log of x + 1

max

public static double max(double a,
                         double b)

Returns the greater of two double values. That is, the result is the argument closer to positive infinity. If the arguments have the same value, the result is that same value. If either value is NaN, then the result is NaN. Unlike the numerical comparison operators, this method considers negative zero to be strictly smaller than positive zero. If one argument is positive zero and the other negative zero, the result is positive zero.

Parameters:: a - an argument.; b - another argument.
Returns:: the larger of a and b.

max

public static float max(float a,
                        float b)

Returns the greater of two float values. That is, the result is the argument closer to positive infinity. If the arguments have the same value, the result is that same value. If either value is NaN, then the result is NaN. Unlike the numerical comparison operators, this method considers negative zero to be strictly smaller than positive zero. If one argument is positive zero and the other negative zero, the result is positive zero.

Parameters:: a - an argument.; b - another argument.
Returns:: the larger of a and b.

max

public static int max(int a,
                      int b)

Returns the greater of two int values. That is, the result is the argument closer to the value of Integer.MAX_VALUE. If the arguments have the same value, the result is that same value.

Parameters:: a - an argument.; b - another argument.
Returns:: the larger of a and b.

max

public static long max(long a,
                       long b)

Returns the greater of two long values. That is, the result is the argument closer to the value of Long.MAX_VALUE. If the arguments have the same value, the result is that same value.

Parameters:: a - an argument.; b - another argument.
Returns:: the larger of a and b.

min

public static double min(double a,
                         double b)

Returns the smaller of two double values. That is, the result is the value closer to negative infinity. If the arguments have the same value, the result is that same value. If either value is NaN, then the result is NaN. Unlike the numerical comparison operators, this method considers negative zero to be strictly smaller than positive zero. If one argument is positive zero and the other is negative zero, the result is negative zero.

Parameters:: a - an argument.; b - another argument.
Returns:: the smaller of a and b.

min

public static float min(float a,
                        float b)

Returns the smaller of two float values. That is, the result is the value closer to negative infinity. If the arguments have the same value, the result is that same value. If either value is NaN, then the result is NaN. Unlike the numerical comparison operators, this method considers negative zero to be strictly smaller than positive zero. If one argument is positive zero and the other is negative zero, the result is negative zero.

Parameters:: a - an argument.; b - another argument.
Returns:: the smaller of a and b.

min

public static int min(int a,
                      int b)

Returns the smaller of two int values. That is, the result the argument closer to the value of Integer.MIN_VALUE. If the arguments have the same value, the result is that same value.

Parameters:: a - an argument.; b - another argument.
Returns:: the smaller of a and b.

min

public static long min(long a,
                       long b)

Returns the smaller of two long values. That is, the result is the argument closer to the value of Long.MIN_VALUE. If the arguments have the same value, the result is that same value.

Parameters:: a - an argument.; b - another argument.
Returns:: the smaller of a and b.

nextAfter

public static double nextAfter(double start,
                               double direction)

Returns the floating-point number adjacent to the first argument in the direction of the second argument. If both arguments compare as equal the second argument is returned.

Special cases:

If either argument is a NaN, then NaN is returned.
If both arguments are signed zeros, {@code direction} is returned unchanged (as implied by the requirement of returning the second argument if the arguments compare as equal).
If {@code start} is ±{@link Double#MIN_VALUE} and {@code direction} has a value such that the result should have a smaller magnitude, then a zero with the same sign as {@code start} is returned.
If {@code start} is infinite and {@code direction} has a value such that the result should have a smaller magnitude, {@link Double#MAX_VALUE} with the same sign as {@code start} is returned.
If {@code start} is equal to ± {@link Double#MAX_VALUE} and {@code direction} has a value such that the result should have a larger magnitude, an infinity with same sign as {@code start} is returned.

Parameters:: start - starting floating-point value; direction - value indicating which of {@code start}'s neighbors or {@code start} should be returned
Returns:: The floating-point number adjacent to {@code start} in the direction of {@code direction}.

nextAfter

public static float nextAfter(float start,
                              double direction)

Returns the floating-point number adjacent to the first argument in the direction of the second argument. If both arguments compare as equal a value equivalent to the second argument is returned.

Special cases:

If either argument is a NaN, then NaN is returned.
If both arguments are signed zeros, a value equivalent to {@code direction} is returned.
If {@code start} is ±{@link Float#MIN_VALUE} and {@code direction} has a value such that the result should have a smaller magnitude, then a zero with the same sign as {@code start} is returned.
If {@code start} is infinite and {@code direction} has a value such that the result should have a smaller magnitude, {@link Float#MAX_VALUE} with the same sign as {@code start} is returned.
If {@code start} is equal to ± {@link Float#MAX_VALUE} and {@code direction} has a value such that the result should have a larger magnitude, an infinity with same sign as {@code start} is returned.

Parameters:: start - starting floating-point value; direction - value indicating which of {@code start}'s neighbors or {@code start} should be returned
Returns:: The floating-point number adjacent to {@code start} in the direction of {@code direction}.

nextUp

public static double nextUp(double d)

Returns the floating-point value adjacent to {@code d} in the direction of positive infinity. This method is semantically equivalent to {@code nextAfter(d, Double.POSITIVE_INFINITY)}; however, a {@code nextUp} implementation may run faster than its equivalent {@code nextAfter} call.

Special Cases:

If the argument is NaN, the result is NaN.
If the argument is positive infinity, the result is positive infinity.
If the argument is zero, the result is {@link Double#MIN_VALUE}

Parameters:: d - starting floating-point value
Returns:: The adjacent floating-point value closer to positive infinity.

nextUp

public static float nextUp(float f)

Returns the floating-point value adjacent to {@code f} in the direction of positive infinity. This method is semantically equivalent to {@code nextAfter(f, Float.POSITIVE_INFINITY)}; however, a {@code nextUp} implementation may run faster than its equivalent {@code nextAfter} call.

Special Cases:

If the argument is NaN, the result is NaN.
If the argument is positive infinity, the result is positive infinity.
If the argument is zero, the result is {@link Float#MIN_VALUE}

Parameters:: f - starting floating-point value
Returns:: The adjacent floating-point value closer to positive infinity.

pow

public static native double pow(double a,
                                double b)

Returns the value of the first argument raised to the power of the second argument. Special cases:

If the second argument is positive or negative zero, then the result is 1.0.
If the second argument is 1.0, then the result is the same as the first argument.
If the second argument is NaN, then the result is NaN.
If the first argument is NaN and the second argument is nonzero, then the result is NaN.
If
- the absolute value of the first argument is greater than 1 and the second argument is positive infinity, or
- the absolute value of the first argument is less than 1 and the second argument is negative infinity,
then the result is positive infinity.
If
- the absolute value of the first argument is greater than 1 and the second argument is negative infinity, or
- the absolute value of the first argument is less than 1 and the second argument is positive infinity,
then the result is positive zero.
If the absolute value of the first argument equals 1 and the second argument is infinite, then the result is NaN.
If
- the first argument is positive zero and the second argument is greater than zero, or
- the first argument is positive infinity and the second argument is less than zero,
then the result is positive zero.
If
- the first argument is positive zero and the second argument is less than zero, or
- the first argument is positive infinity and the second argument is greater than zero,
then the result is positive infinity.
If
- the first argument is negative zero and the second argument is greater than zero but not a finite odd integer, or
- the first argument is negative infinity and the second argument is less than zero but not a finite odd integer,
then the result is positive zero.
If
- the first argument is negative zero and the second argument is a positive finite odd integer, or
- the first argument is negative infinity and the second argument is a negative finite odd integer,
then the result is negative zero.
If
- the first argument is negative zero and the second argument is less than zero but not a finite odd integer, or
- the first argument is negative infinity and the second argument is greater than zero but not a finite odd integer,
then the result is positive infinity.
If
- the first argument is negative zero and the second argument is a negative finite odd integer, or
- the first argument is negative infinity and the second argument is a positive finite odd integer,
then the result is negative infinity.
If the first argument is finite and less than zero
- if the second argument is a finite even integer, the result is equal to the result of raising the absolute value of the first argument to the power of the second argument
- if the second argument is a finite odd integer, the result is equal to the negative of the result of raising the absolute value of the first argument to the power of the second argument
- if the second argument is finite and not an integer, then the result is NaN.
If both arguments are integers, then the result is exactly equal to the mathematical result of raising the first argument to the power of the second argument if that result can in fact be represented exactly as a double value.

(In the foregoing descriptions, a floating-point value is considered to be an integer if and only if it is finite and a fixed point of the method {@link #ceil ceil} or, equivalently, a fixed point of the method {@link #floor floor}. A value is a fixed point of a one-argument method if and only if the result of applying the method to the value is equal to the value.)

Parameters:: a - base.; b - the exponent.
Returns:: the value a^b.

random

public static double random()

Returns a double value with a positive sign, greater than or equal to 0.0 and less than 1.0. Returned values are chosen pseudorandomly with (approximately) uniform distribution from that range.

When this method is first called, it creates a single new pseudorandom-number generator, exactly as if by the expression

new java.util.Random

This new pseudorandom-number generator is used thereafter for all calls to this method and is used nowhere else.

This method is properly synchronized to allow correct use by more than one thread. However, if many threads need to generate pseudorandom numbers at a great rate, it may reduce contention for each thread to have its own pseudorandom number generator.

Returns:: a pseudorandom double greater than or equal to 0.0 and less than 1.0.

rint

public static double rint(double a)

Returns the double value that is closest in value to the argument and is equal to a mathematical integer. If two double values that are mathematical integers are equally close to the value of the argument, the result is the integer value that is even. Special cases:

If the argument value is already equal to a mathematical integer, then the result is the same as the argument.
If the argument is NaN or an infinity or positive zero or negative zero, then the result is the same as the argument.

Parameters:: a - a value.
Returns:: the closest floating-point value to a that is equal to a mathematical integer.

round

public static long round(double a)

Returns the closest long to the argument. The result is rounded to an integer by adding 1/2, taking the floor of the result, and casting the result to type long. In other words, the result is equal to the value of the expression:

(long)Math.floor(a + 0.5d)

Special cases:

If the argument is NaN, the result is 0.
If the argument is negative infinity or any value less than or equal to the value of Long.MIN_VALUE, the result is equal to the value of Long.MIN_VALUE.
If the argument is positive infinity or any value greater than or equal to the value of Long.MAX_VALUE, the result is equal to the value of Long.MAX_VALUE.

Parameters:: a - a floating-point value to be rounded to a long.
Returns:: the value of the argument rounded to the nearest long value.

round

public static int round(float a)

Returns the closest int to the argument. The result is rounded to an integer by adding 1/2, taking the floor of the result, and casting the result to type int. In other words, the result is equal to the value of the expression:

(int)Math.floor(a + 0.5f)

Special cases:

If the argument is NaN, the result is 0.
If the argument is negative infinity or any value less than or equal to the value of Integer.MIN_VALUE, the result is equal to the value of Integer.MIN_VALUE.
If the argument is positive infinity or any value greater than or equal to the value of Integer.MAX_VALUE, the result is equal to the value of Integer.MAX_VALUE.

Parameters:: a - a floating-point value to be rounded to an integer.
Returns:: the value of the argument rounded to the nearest int value.

scalb

public static double scalb(double d,
                           int scaleFactor)

Return {@code d} × 2^{{@code scaleFactor}} rounded as if performed by a single correctly rounded floating-point multiply to a member of the double value set. See the Java Language Specification for a discussion of floating-point value sets. If the exponent of the result is between {@link Double#MIN_EXPONENT} and {@link Double#MAX_EXPONENT}, the answer is calculated exactly. If the exponent of the result would be larger than {@code Double.MAX_EXPONENT}, an infinity is returned. Note that if the result is subnormal, precision may be lost; that is, when {@code scalb(x, n)} is subnormal, {@code scalb(scalb(x, n), -n)} may not equal x. When the result is non-NaN, the result has the same sign as {@code d}.

Special cases:

If the first argument is NaN, NaN is returned.
If the first argument is infinite, then an infinity of the same sign is returned.
If the first argument is zero, then a zero of the same sign is returned.

Parameters:: d - number to be scaled by a power of two.; scaleFactor - power of 2 used to scale {@code d}
Returns:: {@code d} × 2^{{@code scaleFactor}}

scalb

public static float scalb(float f,
                          int scaleFactor)

Return {@code f} × 2^{{@code scaleFactor}} rounded as if performed by a single correctly rounded floating-point multiply to a member of the float value set. See the Java Language Specification for a discussion of floating-point value sets. If the exponent of the result is between {@link Float#MIN_EXPONENT} and {@link Float#MAX_EXPONENT}, the answer is calculated exactly. If the exponent of the result would be larger than {@code Float.MAX_EXPONENT}, an infinity is returned. Note that if the result is subnormal, precision may be lost; that is, when {@code scalb(x, n)} is subnormal, {@code scalb(scalb(x, n), -n)} may not equal x. When the result is non-NaN, the result has the same sign as {@code f}.

Special cases:

If the first argument is NaN, NaN is returned.
If the first argument is infinite, then an infinity of the same sign is returned.
If the first argument is zero, then a zero of the same sign is returned.

Parameters:: f - number to be scaled by a power of two.; scaleFactor - power of 2 used to scale {@code f}
Returns:: {@code f} × 2^{{@code scaleFactor}}

signum

public static double signum(double d)

Returns the signum function of the argument; zero if the argument is zero, 1.0 if the argument is greater than zero, -1.0 if the argument is less than zero.

Special Cases:

If the argument is NaN, then the result is NaN.
If the argument is positive zero or negative zero, then the result is the same as the argument.

Parameters:: d - the floating-point value whose signum is to be returned
Returns:: the signum function of the argument

signum

public static float signum(float f)

Returns the signum function of the argument; zero if the argument is zero, 1.0f if the argument is greater than zero, -1.0f if the argument is less than zero.

Special Cases:

If the argument is NaN, then the result is NaN.
If the argument is positive zero or negative zero, then the result is the same as the argument.

Parameters:: f - the floating-point value whose signum is to be returned
Returns:: the signum function of the argument

sin

public static native double sin(double a)

Returns the trigonometric sine of an angle. Special cases:

If the argument is NaN or an infinity, then the result is NaN.
If the argument is zero, then the result is a zero with the same sign as the argument.

Parameters:: a - an angle, in radians.
Returns:: the sine of the argument.

sinh

public static native double sinh(double x)

Returns the hyperbolic sine of a double value. The hyperbolic sine of x is defined to be (e^x - e^-x)/2 where e is {@linkplain Math#E Euler's number}.

Special cases:

If the argument is NaN, then the result is NaN.
If the argument is infinite, then the result is an infinity with the same sign as the argument.
If the argument is zero, then the result is a zero with the same sign as the argument.

Parameters:: x - The number whose hyperbolic sine is to be returned.
Returns:: The hyperbolic sine of x.

sqrt

public static native double sqrt(double a)

Returns the correctly rounded positive square root of a double value. Special cases:

If the argument is NaN or less than zero, then the result is NaN.
If the argument is positive infinity, then the result is positive infinity.
If the argument is positive zero or negative zero, then the result is the same as the argument.

Otherwise, the result is the double value closest to the true mathematical square root of the argument value.

Parameters:: a - a value.
Returns:: the positive square root of a.

tan

public static native double tan(double a)

Returns the trigonometric tangent of an angle. Special cases:

If the argument is NaN or an infinity, then the result is NaN.
If the argument is zero, then the result is a zero with the same sign as the argument.

Parameters:: a - an angle, in radians.
Returns:: the tangent of the argument.

tanh

public static native double tanh(double x)

Returns the hyperbolic tangent of a double value. The hyperbolic tangent of x is defined to be (e^x - e^-x)/(e^x + e^-x), in other words, {@linkplain Math#sinh sinh(x)}/{@linkplain Math#cosh cosh(x)}. Note that the absolute value of the exact tanh is always less than 1.

Special cases:

If the argument is NaN, then the result is NaN.
If the argument is zero, then the result is a zero with the same sign as the argument.
If the argument is positive infinity, then the result is +1.0.
If the argument is negative infinity, then the result is -1.0.

Parameters:: x - The number whose hyperbolic tangent is to be returned.
Returns:: The hyperbolic tangent of x.

toDegrees

public static double toDegrees(double angrad)

Converts an angle measured in radians to an approximately equivalent angle measured in degrees. The conversion from radians to degrees is generally inexact; users should not expect cos(toRadians(90.0)) to exactly equal 0.0.

Parameters:: angrad - an angle, in radians
Returns:: the measurement of the angle angrad in degrees.

toRadians

public static double toRadians(double angdeg)

Converts an angle measured in degrees to an approximately equivalent angle measured in radians. The conversion from degrees to radians is generally inexact.

Parameters:: angdeg - an angle, in degrees
Returns:: the measurement of the angle angdeg in radians.

ulp

public static double ulp(double d)

Returns the size of an ulp of the argument. An ulp of a double value is the positive distance between this floating-point value and the double value next larger in magnitude. Note that for non-NaN x, ulp(-x) == ulp(x).

Special Cases:

If the argument is NaN, then the result is NaN.
If the argument is positive or negative infinity, then the result is positive infinity.
If the argument is positive or negative zero, then the result is Double.MIN_VALUE.
If the argument is ±Double.MAX_VALUE, then the result is equal to 2⁹⁷¹.

Parameters:: d - the floating-point value whose ulp is to be returned
Returns:: the size of an ulp of the argument

ulp

public static float ulp(float f)

Returns the size of an ulp of the argument. An ulp of a float value is the positive distance between this floating-point value and the float value next larger in magnitude. Note that for non-NaN x, ulp(-x) == ulp(x).

Special Cases:

If the argument is NaN, then the result is NaN.
If the argument is positive or negative infinity, then the result is positive infinity.
If the argument is positive or negative zero, then the result is Float.MIN_VALUE.
If the argument is ±Float.MAX_VALUE, then the result is equal to 2¹⁰⁴.

Parameters:: f - the floating-point value whose ulp is to be returned
Returns:: the size of an ulp of the argument

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java.langclass StrictMath

E

PI

abs

abs

abs

abs

acos

asin

atan

atan2

cbrt

ceil

copySign

copySign

cos

cosh

exp

expm1

floor

getExponent

getExponent

hypot

IEEEremainder

log

log10

log1p

max

max

max

max

min

min

min

min

nextAfter

nextAfter

nextUp

nextUp

pow

random

rint

round

round

scalb

scalb

signum

signum

sin

sinh

sqrt

tan

tanh

toDegrees

toRadians

ulp

ulp

java.lang
class StrictMath