public final class Math extends Object
Math contains methods for performing basic numeric operations such as the
 elementary exponential, logarithm, square root, and trigonometric functions.
 
 Unlike some of the numeric methods of class StrictMath, all implementations of the
 equivalent functions of class Math are not defined to return the bit-for-bit same
 results. This relaxation permits better-performing implementations where strict reproducibility
 is not required.
 
 By default many of the Math methods simply call the equivalent method in
 StrictMath for their implementation. Code generators are encouraged to use
 platform-specific native libraries or microprocessor instructions, where available, to provide
 higher-performance implementations of Math methods. Such higher-performance
 implementations still must conform to the specification for Math.
 
 The quality of implementation specifications concern two properties, accuracy of the returned
 result and monotonicity of the method. Accuracy of the floating-point Math methods is
 measured in terms of ulps, units in the last place. For a given floating-point format, an
 ulp of a specific real number value is the distance between the two floating-point values
 bracketing that numerical value. When discussing the accuracy of a method as a whole rather than
 at a specific argument, the number of ulps cited is for the worst-case error at any argument. If
 a method always has an error less than 0.5 ulps, the method always returns the floating-point
 number nearest the exact result; such a method is correctly rounded. A correctly rounded
 method is generally the best a floating-point approximation can be; however, it is impractical
 for many floating-point methods to be correctly rounded. Instead, for the Math class, a
 larger error bound of 1 or 2 ulps is allowed for certain methods. Informally, with a 1 ulp error
 bound, when the exact result is a representable number, the exact result should be returned as
 the computed result; otherwise, either of the two floating-point values which bracket the exact
 result may be returned. For exact results large in magnitude, one of the endpoints of the bracket
 may be infinite. Besides accuracy at individual arguments, maintaining proper relations between
 the method at different arguments is also important. Therefore, most methods with more than 0.5
 ulp errors are required to be semi-monotonic: whenever the mathematical function is
 non-decreasing, so is the floating-point approximation, likewise, whenever the mathematical
 function is non-increasing, so is the floating-point approximation. Not all approximations that
 have 1 ulp accuracy will automatically meet the monotonicity requirements.
| Modifier and Type | Field and Description | 
|---|---|
| static double | EThe  doublevalue that is closer than any other to e, the base of the natural
 logarithms. | 
| static double | PIThe  doublevalue that is closer than any other to pi, the ratio of the
 circumference of a circle to its diameter. | 
| Modifier and Type | Method and Description | 
|---|---|
| static double | abs(double a)Returns the absolute value of a  doublevalue. | 
| static float | abs(float a)Returns the absolute value of a  floatvalue. | 
| static int | abs(int a)Returns the absolute value of an  intvalue. | 
| static long | abs(long a)Returns the absolute value of a  longvalue. | 
| static double | acos(double a)Returns the arc cosine of a value; the returned angle is in the range 0.0 through pi. | 
| static double | asin(double a)Returns the arc sine of a value; the returned angle is in the range -pi/2 through
 pi/2. | 
| static double | atan(double a)Returns the arc tangent of a value; the returned angle is in the range -pi/2 through
 pi/2. | 
| static double | atan2(double y,
     double x)Returns the angle theta from the conversion of rectangular coordinates ( x,y) to polar coordinates (r, theta). | 
| static double | cbrt(double a)Returns the cube root of a  doublevalue. | 
| static double | ceil(double a)Returns the smallest (closest to negative infinity)  doublevalue 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 double | cos(double a)Returns the trigonometric cosine of an angle. | 
| static double | cosh(double x)Returns the hyperbolic cosine of a  doublevalue. | 
| static double | exp(double a)Returns Euler's number e raised to the power of a  doublevalue. | 
| static double | expm1(double x)Returns ex -1. | 
| static double | floor(double a)Returns the largest (closest to positive infinity)  doublevalue 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  double. | 
| static int | getExponent(float f)Returns the unbiased exponent used in the representation of a  float. | 
| static double | hypot(double x,
     double y)Returns sqrt(x2 +y2) without intermediate overflow or
 underflow. | 
| static double | IEEEremainder(double f1,
             double f2)Computes the remainder operation on two arguments as prescribed by the IEEE 754 standard. | 
| static double | log(double a)Returns the natural logarithm (base e) of a  doublevalue. | 
| static double | log10(double a)Returns the base 10 logarithm of a  doublevalue. | 
| static 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  doublevalues. | 
| static float | max(float a,
   float b)Returns the greater of two  floatvalues. | 
| static int | max(int a,
   int b)Returns the greater of two  intvalues. | 
| static long | max(long a,
   long b)Returns the greater of two  longvalues. | 
| static double | min(double a,
   double b)Returns the smaller of two  doublevalues. | 
| static float | min(float a,
   float b)Returns the smaller of two  floatvalues. | 
| static int | min(int a,
   int b)Returns the smaller of two  intvalues. | 
| static long | min(long a,
   long b)Returns the smaller of two  longvalues. | 
| 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  din the direction of positive infinity. | 
| static float | nextUp(float f)Returns the floating-point value adjacent to  fin the direction of positive infinity. | 
| static 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  doublevalue with a positive sign, greater than or equal to0.0and
 less than1.0. | 
| static double | rint(double a)Returns the  doublevalue that is closest in value to the argument and is equal to a
 mathematical integer. | 
| static long | round(double a)Returns the closest  longto the argument, with ties rounding up. | 
| static int | round(float a)Returns the closest  intto the argument, with ties rounding up. | 
| static double | scalb(double d,
     int scaleFactor)Return  d× 2scaleFactorrounded 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  f× 2scaleFactorrounded 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 double | sin(double a)Returns the trigonometric sine of an angle. | 
| static double | sinh(double x)Returns the hyperbolic sine of a  doublevalue. | 
| static double | sqrt(double a)Returns the correctly rounded positive square root of a  doublevalue. | 
| static double | tan(double a)Returns the trigonometric tangent of an angle. | 
| static double | tanh(double x)Returns the hyperbolic tangent of a  doublevalue. | 
| 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. | 
public static final double E
double value that is closer than any other to e, the base of the natural
 logarithms.public static final double PI
double value that is closer than any other to pi, the ratio of the
 circumference of a circle to its diameter.public static double abs(double 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:
 
 Double.longBitsToDouble((Double.doubleToLongBits(a)<<1)>>>1)
a - the argument whose absolute value is to be determinedpublic static float abs(float 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:
 
 Float.intBitsToFloat(0x7fffffff & Float.floatToIntBits(a))
a - the argument whose absolute value is to be determinedpublic static int abs(int a)
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.
a - the argument whose absolute value is to be determinedpublic static long abs(long 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.
a - the argument whose absolute value is to be determinedpublic static double acos(double a)
The computed result must be within 1 ulp of the exact result. Results must be semi-monotonic.
a - the value whose arc cosine is to be returned.public static double asin(double a)
The computed result must be within 1 ulp of the exact result. Results must be semi-monotonic.
a - the value whose arc sine is to be returned.public static double atan(double a)
The computed result must be within 1 ulp of the exact result. Results must be semi-monotonic.
a - the value whose arc tangent is to be returned.public static double atan2(double y,
                           double x)
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:
 double value closest to pi.
 double value closest to -pi.
 double value closest to pi/2.
 double value closest to -pi/2.
 double value closest
 to pi/4.
 double value closest to 3*pi/4.
 double value closest to -pi/4.
 double value closest
 to -3*pi/4.
 The computed result must be within 2 ulps of the exact result. Results must be semi-monotonic.
y - the ordinate coordinatex - the abscissa coordinatepublic static double cbrt(double 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:
 The computed result must be within 1 ulp of the exact result.
a - a value.a.public static double ceil(double a)
double value that is greater than or
 equal to the argument and is equal to a mathematical integer. Special cases:
 Math.ceil(x) is exactly the value of -Math.floor(-x).a - a value.public static double copySign(double magnitude,
                              double sign)
magnitude - the parameter providing the magnitude of the resultsign - the parameter providing the sign of the resultmagnitude and the sign of sign.public static float copySign(float magnitude,
                             float sign)
magnitude - the parameter providing the magnitude of the resultsign - the parameter providing the sign of the resultmagnitude and the sign of sign.public static double cos(double a)
The computed result must be within 1 ulp of the exact result. Results must be semi-monotonic.
a - an angle, in radians.public static double cosh(double x)
double value. The hyperbolic cosine of x is
 defined to be (ex + e-x)/2 where e is
 Euler's number.
 Special cases:
1.0.
 The computed result must be within 2.5 ulps of the exact result.
x - The number whose hyperbolic cosine is to be returned.x.public static double exp(double a)
double value. Special cases:
 The computed result must be within 1 ulp of the exact result. Results must be semi-monotonic.
a - the exponent to raise e to.a, where e is the base of the natural
         logarithms.public static double expm1(double x)
expm1(x) + 1 is much closer to the true result of ex than
 exp(x).
 Special cases:
 The computed result must be within 1 ulp of the exact result. Results must be semi-monotonic. The
 result of expm1 for any finite input must be greater than or equal to -1.0. Note
 that once the exact result of ex - 1 is within 1/2 ulp of the
 limit value -1, -1.0 should be returned.
x - the exponent to raise e to in the computation of ex
         -1.x - 1.public static double floor(double a)
double value that is less than or
 equal to the argument and is equal to a mathematical integer. Special cases:
 a - a value.public static int getExponent(double d)
double. Special cases:
 Double.MAX_EXPONENT + 1.
 Double.MIN_EXPONENT -1.
 d - a double valuepublic static int getExponent(float f)
float. Special cases:
 Float.MAX_EXPONENT + 1.
 Float.MIN_EXPONENT -1.
 f - a float valuepublic static double hypot(double x,
                           double y)
Special cases:
The computed result must be within 1 ulp of the exact result. If one parameter is held constant, the results must be semi-monotonic in the other parameter.
x - a valuey - a valuepublic static double IEEEremainder(double f1,
                                   double f2)
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:
 f1 - the dividend.f2 - the divisor.f1 is divided by f2.public static double log(double a)
double value. Special cases:
 The computed result must be within 1 ulp of the exact result. Results must be semi-monotonic.
a - a valuea, the natural logarithm of a.public static double log10(double a)
double value. Special cases:
 The computed result must be within 1 ulp of the exact result. Results must be semi-monotonic.
a - a valuea.public static double log1p(double x)
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:
The computed result must be within 1 ulp of the exact result. Results must be semi-monotonic.
x - a valuex + 1), the natural log of x + 1public static double max(double a,
                         double b)
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.a - an argument.b - another argument.a and b.public static float max(float a,
                        float b)
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.a - an argument.b - another argument.a and b.public static int max(int a,
                      int b)
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.a - an argument.b - another argument.a and b.public static long max(long a,
                       long b)
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.a - an argument.b - another argument.a and b.public static double min(double a,
                         double b)
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.a - an argument.b - another argument.a and b.public static float min(float a,
                        float b)
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.a - an argument.b - another argument.a and b.public static int min(int a,
                      int b)
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.a - an argument.b - another argument.a and b.public static long min(long a,
                       long b)
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.a - an argument.b - another argument.a and b.public static double nextAfter(double start,
                               double direction)
Special cases:
direction is returned unchanged (as implied by
 the requirement of returning the second argument if the arguments compare as equal).
 start is ±Double.MIN_VALUE and direction has a value such
 that the result should have a smaller magnitude, then a zero with the same sign as start
 is returned.
 start is infinite and direction has a value such that the result should
 have a smaller magnitude, Double.MAX_VALUE with the same sign as start is
 returned.
 start is equal to ± Double.MAX_VALUE and direction has a
 value such that the result should have a larger magnitude, an infinity with same sign as
 start is returned.
 start - starting floating-point valuedirection - value indicating which of start's neighbors or start should be returnedstart in the direction of
         direction.public static float nextAfter(float start,
                              double direction)
Special cases:
direction is returned.
 start is ±Float.MIN_VALUE and direction has a value such
 that the result should have a smaller magnitude, then a zero with the same sign as start
 is returned.
 start is infinite and direction has a value such that the result should
 have a smaller magnitude, Float.MAX_VALUE with the same sign as start is
 returned.
 start is equal to ± Float.MAX_VALUE and direction has a
 value such that the result should have a larger magnitude, an infinity with same sign as
 start is returned.
 start - starting floating-point valuedirection - value indicating which of start's neighbors or start should be returnedstart in the direction of
         direction.public static double nextUp(double d)
d in the direction of positive infinity.
 This method is semantically equivalent to nextAfter(d,
 Double.POSITIVE_INFINITY); however, a nextUp implementation may run faster than its
 equivalent nextAfter call.
 Special Cases:
Double.MIN_VALUE
 d - starting floating-point valuepublic static float nextUp(float f)
f in the direction of positive infinity.
 This method is semantically equivalent to nextAfter(f,
 Float.POSITIVE_INFINITY); however, a nextUp implementation may run faster than its
 equivalent nextAfter call.
 Special Cases:
Float.MIN_VALUE
 f - starting floating-point valuepublic static double pow(double a,
                         double b)
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 ceil or, equivalently, a fixed
 point of the method 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.)
 
The computed result must be within 1 ulp of the exact result. Results must be semi-monotonic.
a - the base.b - the exponent.ab.public static double random()
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 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.
double greater than or equal to 0.0 and less than
         1.0.Random.nextDouble()public static double rint(double a)
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, the result is the integer value that is even. Special cases:
 a - a double value.a that is equal to a mathematical integer.public static long round(double a)
long to the argument, with ties rounding up.
 Special cases:
Long.MIN_VALUE, the result is equal to the value of Long.MIN_VALUE.
 Long.MAX_VALUE, the result is equal to the value of Long.MAX_VALUE.
 a - a floating-point value to be rounded to a long.long value.Long.MAX_VALUE, 
Long.MIN_VALUEpublic static int round(float a)
int to the argument, with ties rounding up.
 Special cases:
Integer.MIN_VALUE, the result is equal to the value of Integer.MIN_VALUE.
 Integer.MAX_VALUE, the result is equal to the value of Integer.MAX_VALUE.
 a - a floating-point value to be rounded to an integer.int value.Integer.MAX_VALUE, 
Integer.MIN_VALUEpublic static double scalb(double d,
                           int scaleFactor)
d × 2scaleFactor 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 Double.MIN_EXPONENT and Double.MAX_EXPONENT, the answer is
 calculated exactly. If the exponent of the result would be larger than
 Double.MAX_EXPONENT, an infinity is returned. Note that if the result is subnormal,
 precision may be lost; that is, when scalb(x, n) is subnormal,
 scalb(scalb(x, n), -n) may not equal x. When the result is non-NaN, the result has
 the same sign as d.
 Special cases:
d - number to be scaled by a power of two.scaleFactor - power of 2 used to scale dd × 2scaleFactorpublic static float scalb(float f,
                          int scaleFactor)
f × 2scaleFactor 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 Float.MIN_EXPONENT and Float.MAX_EXPONENT, the answer is
 calculated exactly. If the exponent of the result would be larger than
 Float.MAX_EXPONENT, an infinity is returned. Note that if the result is subnormal,
 precision may be lost; that is, when scalb(x, n) is subnormal,
 scalb(scalb(x, n), -n) may not equal x. When the result is non-NaN, the result has
 the same sign as f.
 Special cases:
f - number to be scaled by a power of two.scaleFactor - power of 2 used to scale ff × 2scaleFactorpublic static double signum(double d)
Special Cases:
d - the floating-point value whose signum is to be returnedpublic static float signum(float f)
Special Cases:
f - the floating-point value whose signum is to be returnedpublic static double sin(double a)
The computed result must be within 1 ulp of the exact result. Results must be semi-monotonic.
a - an angle, in radians.public static double sinh(double x)
double value. The hyperbolic sine of x is defined
 to be (ex - e-x)/2 where e is Euler's number.
 Special cases:
The computed result must be within 2.5 ulps of the exact result.
x - The number whose hyperbolic sine is to be returned.x.public static double sqrt(double a)
double value. Special cases:
 double value closest to the true mathematical square root of
 the argument value.a - a value.a. If the argument is NaN or less than zero, the
         result is NaN.public static double tan(double a)
The computed result must be within 1 ulp of the exact result. Results must be semi-monotonic.
a - an angle, in radians.public static double tanh(double x)
double value. The hyperbolic tangent of x is
 defined to be (ex - e-x)/(ex + 
 e-x), in other words, sinh(x)/
 cosh(x). Note that the absolute value of the exact tanh is always
 less than 1.
 Special cases:
+1.0.
 -1.0.
 
 The computed result must be within 2.5 ulps of the exact result. The result of tanh for
 any finite input must have an absolute value less than or equal to 1. Note that once the exact
 result of tanh is within 1/2 of an ulp of the limit value of ±1, correctly signed
 ±1.0 should be returned.
x - The number whose hyperbolic tangent is to be returned.x.public static double toDegrees(double angrad)
cos(toRadians(90.0)) to exactly equal 0.0.angrad - an angle, in radiansangrad in degrees.public static double toRadians(double angdeg)
angdeg - an angle, in degreesangdeg in radians.public static double ulp(double d)
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:
Double.MIN_VALUE.
 Double.MAX_VALUE, then the result is equal to
 2971.
 d - the floating-point value whose ulp is to be returnedpublic static float ulp(float f)
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:
Float.MIN_VALUE.
 Float.MAX_VALUE, then the result is equal to
 2104.
 f - the floating-point value whose ulp is to be returned