StrictMath
public
final
class
StrictMath
extends Object
java.lang.Object | |
↳ | java.lang.StrictMath |
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 to be transliterated into Java and executed
with all floating-point and integer operations following the rules
of Java arithmetic. The following transformations are used in the
transliteration:
- Extraction and setting of the high and low halves of a 64-bit
double
in C is expressed using Java platform methods that perform bit-wise conversions Double.doubleToRawLongBits(double)} and Double.longBitsToDouble(long)}. - Unsigned
int
values in C are mapped to signedint
values in Java with updates to operations to replicate unsigned semantics where the results on the same textual operation would differ. For example,>>
shifts on unsigned C values are replaced with>>>
shifts on signed Java values. Sized comparisons on unsigned C values (<
,<=
,>
,>=
) are replaced with semantically equivalent calls tocompareUnsigned
.
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
.
The platform uses signed two's complement integer arithmetic with
int and long primitive types. The developer should choose
the primitive type to ensure that arithmetic operations consistently
produce correct results, which in some cases means the operations
will not overflow the range of values of the computation.
The best practice is to choose the primitive type and algorithm to avoid
overflow. In cases where the size is int
or long
and
overflow errors need to be detected, the methods whose names end with
Exact
throw an ArithmeticException
when the results overflow.
IEEE 754 Recommended Operations
TheMath
class discusses how the shared
quality of implementation criteria for selected Math
and
StrictMath
methods relate to the IEEE 754
recommended operations.
See also:
Summary
Constants | |
---|---|
double |
E
The |
double |
PI
The |
double |
TAU
The |
Public methods | |
---|---|
static
double
|
IEEEremainder(double f1, double f2)
Computes the remainder operation on two arguments as prescribed by the IEEE 754 standard. |
static
long
|
abs(long a)
Returns the absolute value of a |
static
int
|
abs(int a)
Returns the absolute value of an |
static
double
|
abs(double a)
Returns the absolute value of a |
static
float
|
abs(float a)
Returns the absolute value of a |
static
long
|
absExact(long a)
Returns the mathematical absolute value of an |
static
int
|
absExact(int a)
Returns the mathematical absolute value of an |
static
double
|
acos(double a)
Returns the arc cosine of a value; the returned angle is in the range 0.0 through pi. |
static
int
|
addExact(int x, int y)
Returns the sum of its arguments,
throwing an exception if the result overflows an |
static
long
|
addExact(long x, long y)
Returns the sum of its arguments,
throwing an exception if the result overflows a |
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 ( |
static
double
|
cbrt(double a)
Returns the cube root of a |
static
double
|
ceil(double a)
Returns the smallest (closest to negative infinity)
|
static
long
|
ceilDiv(long x, int y)
Returns the smallest (closest to negative infinity)
|
static
long
|
ceilDiv(long x, long y)
Returns the smallest (closest to negative infinity)
|
static
int
|
ceilDiv(int x, int y)
Returns the smallest (closest to negative infinity)
|
static
long
|
ceilDivExact(long x, long y)
Returns the smallest (closest to negative infinity)
|
static
int
|
ceilDivExact(int x, int y)
Returns the smallest (closest to negative infinity)
|
static
long
|
ceilMod(long x, long y)
Returns the ceiling modulus of the |
static
int
|
ceilMod(int x, int y)
Returns the ceiling modulus of the |
static
int
|
ceilMod(long x, int y)
Returns the ceiling modulus of the |
static
double
|
clamp(double value, double min, double max)
Clamps the value to fit between min and max. |
static
float
|
clamp(float value, float min, float max)
Clamps the value to fit between min and max. |
static
int
|
clamp(long value, int min, int max)
Clamps the value to fit between min and max. |
static
long
|
clamp(long value, long min, long max)
Clamps the value to fit between min and max. |
static
float
|
copySign(float magnitude, float sign)
Returns the first floating-point argument with the sign of the second floating-point argument. |
static
double
|
copySign(double magnitude, double 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 |
static
int
|
decrementExact(int a)
Returns the argument decremented by one,
throwing an exception if the result overflows an |
static
long
|
decrementExact(long a)
Returns the argument decremented by one,
throwing an exception if the result overflows a |
static
long
|
divideExact(long x, long y)
Returns the quotient of the arguments, throwing an exception if the
result overflows a |
static
int
|
divideExact(int x, int y)
Returns the quotient of the arguments, throwing an exception if the
result overflows an |
static
double
|
exp(double a)
Returns Euler's number e raised to the power of a
|
static
double
|
expm1(double x)
Returns ex -1. |
static
double
|
floor(double a)
Returns the largest (closest to positive infinity)
|
static
int
|
floorDiv(int x, int y)
Returns the largest (closest to positive infinity)
|
static
long
|
floorDiv(long x, long y)
Returns the largest (closest to positive infinity)
|
static
long
|
floorDiv(long x, int y)
Returns the largest (closest to positive infinity)
|
static
long
|
floorDivExact(long x, long y)
Returns the largest (closest to positive infinity)
|
static
int
|
floorDivExact(int x, int y)
Returns the largest (closest to positive infinity)
|
static
long
|
floorMod(long x, long y)
Returns the floor modulus of the |
static
int
|
floorMod(int x, int y)
Returns the floor modulus of the |
static
int
|
floorMod(long x, int y)
Returns the floor modulus of the |
static
double
|
fma(double a, double b, double c)
Returns the fused multiply add of the three arguments; that is,
returns the exact product of the first two arguments summed
with the third argument and then rounded once to the nearest
|
static
float
|
fma(float a, float b, float c)
Returns the fused multiply add of the three arguments; that is,
returns the exact product of the first two arguments summed
with the third argument and then rounded once to the nearest
|
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
double
|
hypot(double x, double y)
Returns sqrt(x2 +y2) without intermediate overflow or underflow. |
static
int
|
incrementExact(int a)
Returns the argument incremented by one,
throwing an exception if the result overflows an |
static
long
|
incrementExact(long a)
Returns the argument incremented by one,
throwing an exception if the result overflows a |
static
double
|
log(double a)
Returns the natural logarithm (base e) of a |
static
double
|
log10(double a)
Returns the base 10 logarithm of a |
static
double
|
log1p(double x)
Returns the natural logarithm of the sum of the argument and 1. |
static
long
|
max(long a, long b)
Returns the greater of two |
static
double
|
max(double a, double b)
Returns the greater of two |
static
int
|
max(int a, int b)
Returns the greater of two |
static
float
|
max(float a, float b)
Returns the greater of two |
static
float
|
min(float a, float b)
Returns the smaller of two |
static
int
|
min(int a, int b)
Returns the smaller of two |
static
long
|
min(long a, long b)
Returns the smaller of two |
static
double
|
min(double a, double b)
Returns the smaller of two |
static
int
|
multiplyExact(int x, int y)
Returns the product of the arguments,
throwing an exception if the result overflows an |
static
long
|
multiplyExact(long x, long y)
Returns the product of the arguments,
throwing an exception if the result overflows a |
static
long
|
multiplyExact(long x, int y)
Returns the product of the arguments, throwing an exception if the result
overflows a |
static
long
|
multiplyFull(int x, int y)
Returns the exact mathematical product of the arguments. |
static
long
|
multiplyHigh(long x, long y)
Returns as a |
static
int
|
negateExact(int a)
Returns the negation of the argument,
throwing an exception if the result overflows an |
static
long
|
negateExact(long a)
Returns the negation of the argument,
throwing an exception if the result overflows a |
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
|
nextAfter(double start, double direction)
Returns the floating-point number adjacent to the first argument in the direction of the second argument. |
static
double
|
nextDown(double d)
Returns the floating-point value adjacent to |
static
float
|
nextDown(float f)
Returns the floating-point value adjacent to |
static
double
|
nextUp(double d)
Returns the floating-point value adjacent to |
static
float
|
nextUp(float f)
Returns the floating-point value adjacent to |
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 |
static
double
|
rint(double a)
Returns the |
static
int
|
round(float a)
Returns the closest |
static
long
|
round(double a)
Returns the closest |
static
float
|
scalb(float f, int scaleFactor)
Returns |
static
double
|
scalb(double d, int scaleFactor)
Returns |
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
|
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
double
|
sin(double a)
Returns the trigonometric sine of an angle. |
static
double
|
sinh(double x)
Returns the hyperbolic sine of a |
static
double
|
sqrt(double a)
Returns the correctly rounded positive square root of a
|
static
int
|
subtractExact(int x, int y)
Returns the difference of the arguments,
throwing an exception if the result overflows an |
static
long
|
subtractExact(long x, long y)
Returns the difference of the arguments,
throwing an exception if the result overflows a |
static
double
|
tan(double a)
Returns the trigonometric tangent of an angle. |
static
double
|
tanh(double x)
Returns the hyperbolic tangent of a |
static
double
|
toDegrees(double angrad)
Converts an angle measured in radians to an approximately equivalent angle measured in degrees. |
static
int
|
toIntExact(long value)
Returns the value of the |
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. |
static
long
|
unsignedMultiplyHigh(long x, long y)
Returns as a |
Inherited methods | |
---|---|
Constants
E
public static final double E
The double
value that is closer than any other to
e, the base of the natural logarithms.
Constant Value: 2.718281828459045
PI
public static final double PI
The double
value that is closer than any other to
pi (π), the ratio of the circumference of a circle to its
diameter.
Constant Value: 3.141592653589793
TAU
public static final double TAU
The double
value that is closer than any other to
tau (τ), the ratio of the circumference of a circle
to its radius.
Constant Value: 6.283185307179586
Public methods
IEEEremainder
public static 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 |
double : the dividend. |
f2 |
double : the divisor. |
Returns | |
---|---|
double |
the remainder when f1 is divided by
f2 . |
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. In
contrast, the StrictMath#absExact(long)
method throws
an ArithmeticException
for this value.
Parameters | |
---|---|
a |
long : the argument whose absolute value is to be determined. |
Returns | |
---|---|
long |
the absolute value of the argument. |
See also:
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. In
contrast, the StrictMath#absExact(int)
method throws an
ArithmeticException
for this value.
Parameters | |
---|---|
a |
int : the argument whose absolute value is to be determined. |
Returns | |
---|---|
int |
the absolute value of the argument. |
See also:
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.
API Note:
- As implied by the above, one valid implementation of
this method is given by the expression below which computes a
double
with the same exponent and significand as the argument but with a guaranteed zero sign bit indicating a positive value:
Double.longBitsToDouble((Double.doubleToRawLongBits(a)<<1)>>>1)
Parameters | |
---|---|
a |
double : the argument whose absolute value is to be determined |
Returns | |
---|---|
double |
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.
API Note:
- As implied by the above, one valid implementation of
this method is given by the expression below which computes a
float
with the same exponent and significand as the argument but with a guaranteed zero sign bit indicating a positive value:
Float.intBitsToFloat(0x7fffffff & Float.floatToRawIntBits(a))
Parameters | |
---|---|
a |
float : the argument whose absolute value is to be determined |
Returns | |
---|---|
float |
the absolute value of the argument. |
absExact
public static long absExact (long a)
Returns the mathematical absolute value of an long
value
if it is exactly representable as an long
, throwing
ArithmeticException
if the result overflows the
positive long
range.
Since the range of two's complement integers is asymmetric
with one additional negative value (JLS {@jls 4.2.1}), the
mathematical absolute value of Long#MIN_VALUE
overflows
the positive long
range, so an exception is thrown for
that argument.
Parameters | |
---|---|
a |
long : the argument whose absolute value is to be determined |
Returns | |
---|---|
long |
the absolute value of the argument, unless overflow occurs |
Throws | |
---|---|
ArithmeticException |
if the argument is Long#MIN_VALUE |
See also:
absExact
public static int absExact (int a)
Returns the mathematical absolute value of an int
value
if it is exactly representable as an int
, throwing
ArithmeticException
if the result overflows the
positive int
range.
Since the range of two's complement integers is asymmetric
with one additional negative value (JLS {@jls 4.2.1}), the
mathematical absolute value of Integer#MIN_VALUE
overflows the positive int
range, so an exception is
thrown for that argument.
Parameters | |
---|---|
a |
int : the argument whose absolute value is to be determined |
Returns | |
---|---|
int |
the absolute value of the argument, unless overflow occurs |
Throws | |
---|---|
ArithmeticException |
if the argument is Integer#MIN_VALUE |
See also:
acos
public static 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.
- If the argument is
1.0
, the result is positive zero.
Parameters | |
---|---|
a |
double : the value whose arc cosine is to be returned. |
Returns | |
---|---|
double |
the arc cosine of the argument. |
addExact
public static int addExact (int x, int y)
Returns the sum of its arguments,
throwing an exception if the result overflows an int
.
Parameters | |
---|---|
x |
int : the first value |
y |
int : the second value |
Returns | |
---|---|
int |
the result |
Throws | |
---|---|
ArithmeticException |
if the result overflows an int |
See also:
addExact
public static long addExact (long x, long y)
Returns the sum of its arguments,
throwing an exception if the result overflows a long
.
Parameters | |
---|---|
x |
long : the first value |
y |
long : the second value |
Returns | |
---|---|
long |
the result |
Throws | |
---|---|
ArithmeticException |
if the result overflows a long |
See also:
asin
public static 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 |
double : the value whose arc sine is to be returned. |
Returns | |
---|---|
double |
the arc sine of the argument. |
atan
public static 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.
- If the argument is infinite, then the result is the closest value to pi/2 with the same sign as the input.
Parameters | |
---|---|
a |
double : the value whose arc tangent is to be returned. |
Returns | |
---|---|
double |
the arc tangent of the argument. |
atan2
public static 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.
API Note:
- For y with a positive sign and finite nonzero
x, the exact mathematical value of
atan2
is equal to:- If x > 0, atan(abs(y/x))
- If x < 0, π - atan(abs(y/x))
Parameters | |
---|---|
y |
double : the ordinate coordinate |
x |
double : the abscissa coordinate |
Returns | |
---|---|
double |
the theta component of the point (r, theta) in polar coordinates that corresponds to the point (x, y) in Cartesian coordinates. |
cbrt
public static 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 |
double : a value. |
Returns | |
---|---|
double |
the cube root of a . |
ceil
public static 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.
StrictMath.ceil(x)
is exactly the
value of -StrictMath.floor(-x)
.
Parameters | |
---|---|
a |
double : a value. |
Returns | |
---|---|
double |
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. |
ceilDiv
public static long ceilDiv (long x, int y)
Returns the smallest (closest to negative infinity)
long
value that is greater than or equal to the algebraic quotient.
There is one special case: if the dividend is
Long.MIN_VALUE and the divisor is -1
,
then integer overflow occurs and
the result is equal to Long.MIN_VALUE
.
See Math.ceilDiv
for examples and
a comparison to the integer division /
operator.
Parameters | |
---|---|
x |
long : the dividend |
y |
int : the divisor |
Returns | |
---|---|
long |
the smallest (closest to negative infinity)
long value that is greater than or equal to the algebraic quotient. |
Throws | |
---|---|
ArithmeticException |
if the divisor y is zero |
See also:
ceilDiv
public static long ceilDiv (long x, long y)
Returns the smallest (closest to negative infinity)
long
value that is greater than or equal to the algebraic quotient.
There is one special case: if the dividend is
Long.MIN_VALUE and the divisor is -1
,
then integer overflow occurs and
the result is equal to Long.MIN_VALUE
.
See Math.ceilDiv
for examples and
a comparison to the integer division /
operator.
Parameters | |
---|---|
x |
long : the dividend |
y |
long : the divisor |
Returns | |
---|---|
long |
the smallest (closest to negative infinity)
long value that is greater than or equal to the algebraic quotient. |
Throws | |
---|---|
ArithmeticException |
if the divisor y is zero |
ceilDiv
public static int ceilDiv (int x, int y)
Returns the smallest (closest to negative infinity)
int
value that is greater than or equal to the algebraic quotient.
There is one special case: if the dividend is
Integer.MIN_VALUE and the divisor is -1
,
then integer overflow occurs and
the result is equal to Integer.MIN_VALUE
.
See Math.ceilDiv
for examples and
a comparison to the integer division /
operator.
Parameters | |
---|---|
x |
int : the dividend |
y |
int : the divisor |
Returns | |
---|---|
int |
the smallest (closest to negative infinity)
int value that is greater than or equal to the algebraic quotient. |
Throws | |
---|---|
ArithmeticException |
if the divisor y is zero |
See also:
ceilDivExact
public static long ceilDivExact (long x, long y)
Returns the smallest (closest to negative infinity)
long
value that is greater than or equal to the algebraic quotient.
This method is identical to ceilDiv(long, long)
except that it
throws an ArithmeticException
when the dividend is
Long.MIN_VALUE and the divisor is
-1
instead of ignoring the integer overflow and returning
Long.MIN_VALUE
.
The ceil modulus method ceilMod(long, long)
is a suitable
counterpart both for this method and for the ceilDiv(long, long)
method.
For examples, see Math.ceilDiv
.
Parameters | |
---|---|
x |
long : the dividend |
y |
long : the divisor |
Returns | |
---|---|
long |
the smallest (closest to negative infinity)
long value that is greater than or equal to the algebraic quotient. |
Throws | |
---|---|
ArithmeticException |
if the divisor y is zero, or the
dividend x is Long.MIN_VALUE and the divisor y
is -1 . |
ceilDivExact
public static int ceilDivExact (int x, int y)
Returns the smallest (closest to negative infinity)
int
value that is greater than or equal to the algebraic quotient.
This method is identical to ceilDiv(int, int)
except that it
throws an ArithmeticException
when the dividend is
Integer.MIN_VALUE and the divisor is
-1
instead of ignoring the integer overflow and returning
Integer.MIN_VALUE
.
The ceil modulus method ceilMod(int, int)
is a suitable
counterpart both for this method and for the ceilDiv(int, int)
method.
See Math.ceilDiv
for examples and
a comparison to the integer division /
operator.
Parameters | |
---|---|
x |
int : the dividend |
y |
int : the divisor |
Returns | |
---|---|
int |
the smallest (closest to negative infinity)
int value that is greater than or equal to the algebraic quotient. |
Throws | |
---|---|
ArithmeticException |
if the divisor y is zero, or the
dividend x is Integer.MIN_VALUE and the divisor y
is -1 . |
See also:
ceilMod
public static long ceilMod (long x, long y)
Returns the ceiling modulus of the long
arguments.
The ceiling modulus is r = x - (ceilDiv(x, y) * y)
,
has the opposite sign as the divisor y
or is zero, and
is in the range of -abs(y) < r < +abs(y)
.
The relationship between ceilDiv
and ceilMod
is such that:
ceilDiv(x, y) * y + ceilMod(x, y) == x
See Math.ceilMod
for examples and
a comparison to the %
operator.
Parameters | |
---|---|
x |
long : the dividend |
y |
long : the divisor |
Returns | |
---|---|
long |
the ceiling modulus x - (ceilDiv(x, y) * y) |
Throws | |
---|---|
ArithmeticException |
if the divisor y is zero |
ceilMod
public static int ceilMod (int x, int y)
Returns the ceiling modulus of the int
arguments.
The ceiling modulus is r = x - (ceilDiv(x, y) * y)
,
has the opposite sign as the divisor y
or is zero, and
is in the range of -abs(y) < r < +abs(y)
.
The relationship between ceilDiv
and ceilMod
is such that:
ceilDiv(x, y) * y + ceilMod(x, y) == x
See Math.ceilMod
for examples and
a comparison to the %
operator.
Parameters | |
---|---|
x |
int : the dividend |
y |
int : the divisor |
Returns | |
---|---|
int |
the ceiling modulus x - (ceilDiv(x, y) * y) |
Throws | |
---|---|
ArithmeticException |
if the divisor y is zero |
See also:
ceilMod
public static int ceilMod (long x, int y)
Returns the ceiling modulus of the long
and int
arguments.
The ceiling modulus is r = x - (ceilDiv(x, y) * y)
,
has the opposite sign as the divisor y
or is zero, and
is in the range of -abs(y) < r < +abs(y)
.
The relationship between ceilDiv
and ceilMod
is such that:
ceilDiv(x, y) * y + ceilMod(x, y) == x
See Math.ceilMod
for examples and
a comparison to the %
operator.
Parameters | |
---|---|
x |
long : the dividend |
y |
int : the divisor |
Returns | |
---|---|
int |
the ceiling modulus x - (ceilDiv(x, y) * y) |
Throws | |
---|---|
ArithmeticException |
if the divisor y is zero |
clamp
public static double clamp (double value, double min, double max)
Clamps the value to fit between min and max. If the value is less
than min
, then min
is returned. If the value is greater
than max
, then max
is returned. Otherwise, the original
value is returned. If value is NaN, the result is also NaN.
Unlike the numerical comparison operators, this method considers
negative zero to be strictly smaller than positive zero.
E.g., clamp(-0.0, 0.0, 1.0)
returns 0.0.
Parameters | |
---|---|
value |
double : value to clamp |
min |
double : minimal allowed value |
max |
double : maximal allowed value |
Returns | |
---|---|
double |
a clamped value that fits into min..max interval |
Throws | |
---|---|
IllegalArgumentException |
if either of min and max
arguments is NaN, or min > max , or min is +0.0, and
max is -0.0. |
clamp
public static float clamp (float value, float min, float max)
Clamps the value to fit between min and max. If the value is less
than min
, then min
is returned. If the value is greater
than max
, then max
is returned. Otherwise, the original
value is returned. If value is NaN, the result is also NaN.
Unlike the numerical comparison operators, this method considers
negative zero to be strictly smaller than positive zero.
E.g., clamp(-0.0f, 0.0f, 1.0f)
returns 0.0f.
Parameters | |
---|---|
value |
float : value to clamp |
min |
float : minimal allowed value |
max |
float : maximal allowed value |
Returns | |
---|---|
float |
a clamped value that fits into min..max interval |
Throws | |
---|---|
IllegalArgumentException |
if either of min and max
arguments is NaN, or min > max , or min is +0.0f, and
max is -0.0f. |
clamp
public static int clamp (long value, int min, int max)
Clamps the value to fit between min and max. If the value is less
than min
, then min
is returned. If the value is greater
than max
, then max
is returned. Otherwise, the original
value is returned.
While the original value of type long may not fit into the int type, the bounds have the int type, so the result always fits the int type. This allows to use method to safely cast long value to int with saturation.
Parameters | |
---|---|
value |
long : value to clamp |
min |
int : minimal allowed value |
max |
int : maximal allowed value |
Returns | |
---|---|
int |
a clamped value that fits into min..max interval |
Throws | |
---|---|
IllegalArgumentException |
if min > max |
clamp
public static long clamp (long value, long min, long max)
Clamps the value to fit between min and max. If the value is less
than min
, then min
is returned. If the value is greater
than max
, then max
is returned. Otherwise, the original
value is returned.
Parameters | |
---|---|
value |
long : value to clamp |
min |
long : minimal allowed value |
max |
long : maximal allowed value |
Returns | |
---|---|
long |
a clamped value that fits into min..max interval |
Throws | |
---|---|
IllegalArgumentException |
if min > max |
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
sign
argument is always treated as if it were
positive.
Parameters | |
---|---|
magnitude |
float : the parameter providing the magnitude of the result |
sign |
float : the parameter providing the sign of the result |
Returns | |
---|---|
float |
a value with the magnitude of magnitude
and the sign of sign . |
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
sign
argument is always treated as if it were
positive.
Parameters | |
---|---|
magnitude |
double : the parameter providing the magnitude of the result |
sign |
double : the parameter providing the sign of the result |
Returns | |
---|---|
double |
a value with the magnitude of magnitude
and the sign of sign . |
cos
public static 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.
- If the argument is zero, then the result is
1.0
.
Parameters | |
---|---|
a |
double : an angle, in radians. |
Returns | |
---|---|
double |
the cosine of the argument. |
cosh
public static double cosh (double x)
Returns the hyperbolic cosine of a double
value.
The hyperbolic cosine of x is defined to be
(ex + e-x)/2
where e is 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 |
double : The number whose hyperbolic cosine is to be returned. |
Returns | |
---|---|
double |
The hyperbolic cosine of x . |
decrementExact
public static int decrementExact (int a)
Returns the argument decremented by one,
throwing an exception if the result overflows an int
.
The overflow only occurs for the minimum value.
Parameters | |
---|---|
a |
int : the value to decrement |
Returns | |
---|---|
int |
the result |
Throws | |
---|---|
ArithmeticException |
if the result overflows an int |
See also:
decrementExact
public static long decrementExact (long a)
Returns the argument decremented by one,
throwing an exception if the result overflows a long
.
The overflow only occurs for the minimum value.
Parameters | |
---|---|
a |
long : the value to decrement |
Returns | |
---|---|
long |
the result |
Throws | |
---|---|
ArithmeticException |
if the result overflows a long |
See also:
divideExact
public static long divideExact (long x, long y)
Returns the quotient of the arguments, throwing an exception if the
result overflows a long
. Such overflow occurs in this method if
x
is Long#MIN_VALUE
and y
is -1
.
In contrast, if Long.MIN_VALUE / -1
were evaluated directly,
the result would be Long.MIN_VALUE
and no exception would be
thrown.
If y
is zero, an ArithmeticException
is thrown
(JLS {@jls 15.17.2}).
The built-in remainder operator "%
" is a suitable counterpart
both for this method and for the built-in division operator "/
".
Parameters | |
---|---|
x |
long : the dividend |
y |
long : the divisor |
Returns | |
---|---|
long |
the quotient x / y |
Throws | |
---|---|
ArithmeticException |
if y is zero or the quotient
overflows a long |
See also:
divideExact
public static int divideExact (int x, int y)
Returns the quotient of the arguments, throwing an exception if the
result overflows an int
. Such overflow occurs in this method if
x
is Integer#MIN_VALUE
and y
is -1
.
In contrast, if Integer.MIN_VALUE / -1
were evaluated directly,
the result would be Integer.MIN_VALUE
and no exception would be
thrown.
If y
is zero, an ArithmeticException
is thrown
(JLS {@jls 15.17.2}).
The built-in remainder operator "%
" is a suitable counterpart
both for this method and for the built-in division operator "/
".
Parameters | |
---|---|
x |
int : the dividend |
y |
int : the divisor |
Returns | |
---|---|
int |
the quotient x / y |
Throws | |
---|---|
ArithmeticException |
if y is zero or the quotient
overflows an int |
See also:
exp
public static 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.
- If the argument is zero, then the result is
1.0
.
Parameters | |
---|---|
a |
double : the exponent to raise e to. |
Returns | |
---|---|
double |
the value ea ,
where e is the base of the natural logarithms. |
expm1
public static double expm1 (double x)
Returns ex -1. Note that for values of
x near 0, the exact sum of
expm1(x)
+ 1 is much closer to the true
result of ex 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 |
double : the exponent to raise e to in the computation of
ex -1. |
Returns | |
---|---|
double |
the value ex - 1. |
floor
public static 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 |
double : a value. |
Returns | |
---|---|
double |
the largest (closest to positive infinity) floating-point value that less than or equal to the argument and is equal to a mathematical integer. |
floorDiv
public static int floorDiv (int x, int y)
Returns the largest (closest to positive infinity)
int
value that is less than or equal to the algebraic quotient.
There is one special case: if the dividend is
Integer.MIN_VALUE and the divisor is -1
,
then integer overflow occurs and
the result is equal to Integer.MIN_VALUE
.
See Math.floorDiv
for examples and
a comparison to the integer division /
operator.
Parameters | |
---|---|
x |
int : the dividend |
y |
int : the divisor |
Returns | |
---|---|
int |
the largest (closest to positive infinity)
int value that is less than or equal to the algebraic quotient. |
Throws | |
---|---|
ArithmeticException |
if the divisor y is zero |
floorDiv
public static long floorDiv (long x, long y)
Returns the largest (closest to positive infinity)
long
value that is less than or equal to the algebraic quotient.
There is one special case: if the dividend is
Long.MIN_VALUE and the divisor is -1
,
then integer overflow occurs and
the result is equal to Long.MIN_VALUE
.
See Math.floorDiv
for examples and
a comparison to the integer division /
operator.
Parameters | |
---|---|
x |
long : the dividend |
y |
long : the divisor |
Returns | |
---|---|
long |
the largest (closest to positive infinity)
long value that is less than or equal to the algebraic quotient. |
Throws | |
---|---|
ArithmeticException |
if the divisor y is zero |
floorDiv
public static long floorDiv (long x, int y)
Returns the largest (closest to positive infinity)
long
value that is less than or equal to the algebraic quotient.
There is one special case: if the dividend is
Long.MIN_VALUE and the divisor is -1
,
then integer overflow occurs and
the result is equal to Long.MIN_VALUE
.
See Math.floorDiv
for examples and
a comparison to the integer division /
operator.
Parameters | |
---|---|
x |
long : the dividend |
y |
int : the divisor |
Returns | |
---|---|
long |
the largest (closest to positive infinity)
long value that is less than or equal to the algebraic quotient. |
Throws | |
---|---|
ArithmeticException |
if the divisor y is zero |
floorDivExact
public static long floorDivExact (long x, long y)
Returns the largest (closest to positive infinity)
long
value that is less than or equal to the algebraic quotient.
This method is identical to floorDiv(long, long)
except that it
throws an ArithmeticException
when the dividend is
Long.MIN_VALUE and the divisor is
-1
instead of ignoring the integer overflow and returning
Long.MIN_VALUE
.
The floor modulus method floorMod(long, long)
is a suitable
counterpart both for this method and for the floorDiv(long, long)
method.
For examples, see Math.floorDiv
.
Parameters | |
---|---|
x |
long : the dividend |
y |
long : the divisor |
Returns | |
---|---|
long |
the largest (closest to positive infinity)
long value that is less than or equal to the algebraic quotient. |
Throws | |
---|---|
ArithmeticException |
if the divisor y is zero, or the
dividend x is Long.MIN_VALUE and the divisor y
is -1 . |
floorDivExact
public static int floorDivExact (int x, int y)
Returns the largest (closest to positive infinity)
int
value that is less than or equal to the algebraic quotient.
This method is identical to floorDiv(int, int)
except that it
throws an ArithmeticException
when the dividend is
Integer.MIN_VALUE and the divisor is
-1
instead of ignoring the integer overflow and returning
Integer.MIN_VALUE
.
The floor modulus method floorMod(int, int)
is a suitable
counterpart both for this method and for the floorDiv(int, int)
method.
See Math.floorDiv
for examples and
a comparison to the integer division /
operator.
Parameters | |
---|---|
x |
int : the dividend |
y |
int : the divisor |
Returns | |
---|---|
int |
the largest (closest to positive infinity)
int value that is less than or equal to the algebraic quotient. |
Throws | |
---|---|
ArithmeticException |
if the divisor y is zero, or the
dividend x is Integer.MIN_VALUE and the divisor y
is -1 . |
See also:
floorMod
public static long floorMod (long x, long y)
Returns the floor modulus of the long
arguments.
The floor modulus is r = x - (floorDiv(x, y) * y)
,
has the same sign as the divisor y
or is zero, and
is in the range of -abs(y) < r < +abs(y)
.
The relationship between floorDiv
and floorMod
is such that:
floorDiv(x, y) * y + floorMod(x, y) == x
See Math.floorMod
for examples and
a comparison to the %
operator.
Parameters | |
---|---|
x |
long : the dividend |
y |
long : the divisor |
Returns | |
---|---|
long |
the floor modulus x - (floorDiv(x, y) * y) |
Throws | |
---|---|
ArithmeticException |
if the divisor y is zero |
floorMod
public static int floorMod (int x, int y)
Returns the floor modulus of the int
arguments.
The floor modulus is r = x - (floorDiv(x, y) * y)
,
has the same sign as the divisor y
or is zero, and
is in the range of -abs(y) < r < +abs(y)
.
The relationship between floorDiv
and floorMod
is such that:
floorDiv(x, y) * y + floorMod(x, y) == x
See Math.floorMod
for examples and
a comparison to the %
operator.
Parameters | |
---|---|
x |
int : the dividend |
y |
int : the divisor |
Returns | |
---|---|
int |
the floor modulus x - (floorDiv(x, y) * y) |
Throws | |
---|---|
ArithmeticException |
if the divisor y is zero |
floorMod
public static int floorMod (long x, int y)
Returns the floor modulus of the long
and int
arguments.
The floor modulus is r = x - (floorDiv(x, y) * y)
,
has the same sign as the divisor y
or is zero, and
is in the range of -abs(y) < r < +abs(y)
.
The relationship between floorDiv
and floorMod
is such that:
floorDiv(x, y) * y + floorMod(x, y) == x
See Math.floorMod
for examples and
a comparison to the %
operator.
Parameters | |
---|---|
x |
long : the dividend |
y |
int : the divisor |
Returns | |
---|---|
int |
the floor modulus x - (floorDiv(x, y) * y) |
Throws | |
---|---|
ArithmeticException |
if the divisor y is zero |
fma
public static double fma (double a, double b, double c)
Returns the fused multiply add of the three arguments; that is,
returns the exact product of the first two arguments summed
with the third argument and then rounded once to the nearest
double
.
The rounding is done using the round to nearest even
rounding mode.
In contrast, if a * b + c
is evaluated as a regular
floating-point expression, two rounding errors are involved,
the first for the multiply operation, the second for the
addition operation.
Special cases:
- If any argument is NaN, the result is NaN.
- If one of the first two arguments is infinite and the other is zero, the result is NaN.
- If the exact product of the first two arguments is infinite (in other words, at least one of the arguments is infinite and the other is neither zero nor NaN) and the third argument is an infinity of the opposite sign, the result is NaN.
Note that fusedMac(a, 1.0, c)
returns the same
result as (a + c
). However,
fusedMac(a, b, +0.0)
does not always return the
same result as (a * b
) since
fusedMac(-0.0, +0.0, +0.0)
is +0.0
while
(-0.0 * +0.0
) is -0.0
; fusedMac(a, b, -0.0)
is
equivalent to (a * b
) however.
API Note:
- This method corresponds to the fusedMultiplyAdd operation defined in IEEE 754-2008.
Parameters | |
---|---|
a |
double : a value |
b |
double : a value |
c |
double : a value |
Returns | |
---|---|
double |
(a × b + c)
computed, as if with unlimited range and precision, and rounded
once to the nearest double value |
fma
public static float fma (float a, float b, float c)
Returns the fused multiply add of the three arguments; that is,
returns the exact product of the first two arguments summed
with the third argument and then rounded once to the nearest
float
.
The rounding is done using the round to nearest even
rounding mode.
In contrast, if a * b + c
is evaluated as a regular
floating-point expression, two rounding errors are involved,
the first for the multiply operation, the second for the
addition operation.
Special cases:
- If any argument is NaN, the result is NaN.
- If one of the first two arguments is infinite and the other is zero, the result is NaN.
- If the exact product of the first two arguments is infinite (in other words, at least one of the arguments is infinite and the other is neither zero nor NaN) and the third argument is an infinity of the opposite sign, the result is NaN.
Note that fma(a, 1.0f, c)
returns the same
result as (a + c
). However,
fma(a, b, +0.0f)
does not always return the
same result as (a * b
) since
fma(-0.0f, +0.0f, +0.0f)
is +0.0f
while
(-0.0f * +0.0f
) is -0.0f
; fma(a, b, -0.0f)
is
equivalent to (a * b
) however.
API Note:
- This method corresponds to the fusedMultiplyAdd operation defined in IEEE 754-2008.
Parameters | |
---|---|
a |
float : a value |
b |
float : a value |
c |
float : a value |
Returns | |
---|---|
float |
(a × b + c)
computed, as if with unlimited range and precision, and rounded
once to the nearest float value |
getExponent
public static int getExponent (double d)
Returns the unbiased exponent used in the representation of a
double
. Special cases:
- If the argument is NaN or infinite, then the result is
Double#MAX_EXPONENT
+ 1. - If the argument is zero or subnormal, then the result is
Double#MIN_EXPONENT
-1.
Parameters | |
---|---|
d |
double : a double value |
Returns | |
---|---|
int |
the unbiased exponent of the argument |
getExponent
public static int getExponent (float f)
Returns the unbiased exponent used in the representation of a
float
. Special cases:
- If the argument is NaN or infinite, then the result is
Float#MAX_EXPONENT
+ 1. - If the argument is zero or subnormal, then the result is
Float#MIN_EXPONENT
-1.
Parameters | |
---|---|
f |
float : a float value |
Returns | |
---|---|
int |
the unbiased exponent of the argument |
hypot
public static 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.
- If both arguments are zero, the result is positive zero.
Parameters | |
---|---|
x |
double : a value |
y |
double : a value |
Returns | |
---|---|
double |
sqrt(x2 +y2) without intermediate overflow or underflow |
incrementExact
public static int incrementExact (int a)
Returns the argument incremented by one,
throwing an exception if the result overflows an int
.
The overflow only occurs for the maximum value.
Parameters | |
---|---|
a |
int : the value to increment |
Returns | |
---|---|
int |
the result |
Throws | |
---|---|
ArithmeticException |
if the result overflows an int |
See also:
incrementExact
public static long incrementExact (long a)
Returns the argument incremented by one,
throwing an exception if the result overflows a long
.
The overflow only occurs for the maximum value.
Parameters | |
---|---|
a |
long : the value to increment |
Returns | |
---|---|
long |
the result |
Throws | |
---|---|
ArithmeticException |
if the result overflows a long |
See also:
log
public static 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.
- If the argument is
1.0
, then the result is positive zero.
Parameters | |
---|---|
a |
double : a value |
Returns | |
---|---|
double |
the value ln a , the natural logarithm of
a . |
log10
public static 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. In particular,
if the argument is
1.0
(100), then the result is positive zero.
Parameters | |
---|---|
a |
double : a value |
Returns | |
---|---|
double |
the base 10 logarithm of a . |
log1p
public static 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 |
double : a value |
Returns | |
---|---|
double |
the value ln(x + 1), the natural
log of x + 1 |
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 |
long : an argument. |
b |
long : another argument. |
Returns | |
---|---|
long |
the larger of a and b . |
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 |
double : an argument. |
b |
double : another argument. |
Returns | |
---|---|
double |
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 |
int : an argument. |
b |
int : another argument. |
Returns | |
---|---|
int |
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 |
float : an argument. |
b |
float : another argument. |
Returns | |
---|---|
float |
the larger 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 |
float : an argument. |
b |
float : another argument. |
Returns | |
---|---|
float |
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 |
int : an argument. |
b |
int : another argument. |
Returns | |
---|---|
int |
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 |
long : an argument. |
b |
long : another argument. |
Returns | |
---|---|
long |
the smaller 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 |
double : an argument. |
b |
double : another argument. |
Returns | |
---|---|
double |
the smaller of a and b . |
multiplyExact
public static int multiplyExact (int x, int y)
Returns the product of the arguments,
throwing an exception if the result overflows an int
.
Parameters | |
---|---|
x |
int : the first value |
y |
int : the second value |
Returns | |
---|---|
int |
the result |
Throws | |
---|---|
ArithmeticException |
if the result overflows an int |
See also:
multiplyExact
public static long multiplyExact (long x, long y)
Returns the product of the arguments,
throwing an exception if the result overflows a long
.
Parameters | |
---|---|
x |
long : the first value |
y |
long : the second value |
Returns | |
---|---|
long |
the result |
Throws | |
---|---|
ArithmeticException |
if the result overflows a long |
See also:
multiplyExact
public static long multiplyExact (long x, int y)
Returns the product of the arguments, throwing an exception if the result
overflows a long
.
Parameters | |
---|---|
x |
long : the first value |
y |
int : the second value |
Returns | |
---|---|
long |
the result |
Throws | |
---|---|
ArithmeticException |
if the result overflows a long |
See also:
multiplyFull
public static long multiplyFull (int x, int y)
Returns the exact mathematical product of the arguments.
Parameters | |
---|---|
x |
int : the first value |
y |
int : the second value |
Returns | |
---|---|
long |
the result |
See also:
multiplyHigh
public static long multiplyHigh (long x, long y)
Returns as a long
the most significant 64 bits of the 128-bit
product of two 64-bit factors.
Parameters | |
---|---|
x |
long : the first value |
y |
long : the second value |
Returns | |
---|---|
long |
the result |
negateExact
public static int negateExact (int a)
Returns the negation of the argument,
throwing an exception if the result overflows an int
.
The overflow only occurs for the minimum value.
Parameters | |
---|---|
a |
int : the value to negate |
Returns | |
---|---|
int |
the result |
Throws | |
---|---|
ArithmeticException |
if the result overflows an int |
See also:
negateExact
public static long negateExact (long a)
Returns the negation of the argument,
throwing an exception if the result overflows a long
.
The overflow only occurs for the minimum value.
Parameters | |
---|---|
a |
long : the value to negate |
Returns | |
---|---|
long |
the result |
Throws | |
---|---|
ArithmeticException |
if the result overflows a long |
See also:
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
direction
is returned. - If
start
is ±Float#MIN_VALUE
anddirection
has a value such that the result should have a smaller magnitude, then a zero with the same sign asstart
is returned. - If
start
is infinite anddirection
has a value such that the result should have a smaller magnitude,Float#MAX_VALUE
with the same sign asstart
is returned. - If
start
is equal to ±Float#MAX_VALUE
anddirection
has a value such that the result should have a larger magnitude, an infinity with same sign asstart
is returned.
Parameters | |
---|---|
start |
float : starting floating-point value |
direction |
double : value indicating which of
start 's neighbors or start should
be returned |
Returns | |
---|---|
float |
The floating-point number adjacent to start in the
direction of direction . |
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,
direction
is returned unchanged (as implied by the requirement of returning the second argument if the arguments compare as equal). - If
start
is ±Double#MIN_VALUE
anddirection
has a value such that the result should have a smaller magnitude, then a zero with the same sign asstart
is returned. - If
start
is infinite anddirection
has a value such that the result should have a smaller magnitude,Double#MAX_VALUE
with the same sign asstart
is returned. - If
start
is equal to ±Double#MAX_VALUE
anddirection
has a value such that the result should have a larger magnitude, an infinity with same sign asstart
is returned.
Parameters | |
---|---|
start |
double : starting floating-point value |
direction |
double : value indicating which of
start 's neighbors or start should
be returned |
Returns | |
---|---|
double |
The floating-point number adjacent to start in the
direction of direction . |
nextDown
public static double nextDown (double d)
Returns the floating-point value adjacent to d
in
the direction of negative infinity. This method is
semantically equivalent to nextAfter(d,
Double.NEGATIVE_INFINITY)
; however, a
nextDown
implementation may run faster than its
equivalent nextAfter
call.
Special Cases:
- If the argument is NaN, the result is NaN.
- If the argument is negative infinity, the result is negative infinity.
- If the argument is zero, the result is
-Double.MIN_VALUE
Parameters | |
---|---|
d |
double : starting floating-point value |
Returns | |
---|---|
double |
The adjacent floating-point value closer to negative infinity. |
nextDown
public static float nextDown (float f)
Returns the floating-point value adjacent to f
in
the direction of negative infinity. This method is
semantically equivalent to nextAfter(f,
Float.NEGATIVE_INFINITY)
; however, a
nextDown
implementation may run faster than its
equivalent nextAfter
call.
Special Cases:
- If the argument is NaN, the result is NaN.
- If the argument is negative infinity, the result is negative infinity.
- If the argument is zero, the result is
-Float.MIN_VALUE
Parameters | |
---|---|
f |
float : starting floating-point value |
Returns | |
---|---|
float |
The adjacent floating-point value closer to negative infinity. |
nextUp
public static double nextUp (double d)
Returns the floating-point value adjacent to 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:
- 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
Double#MIN_VALUE
Parameters | |
---|---|
d |
double : starting floating-point value |
Returns | |
---|---|
double |
The adjacent floating-point value closer to positive infinity. |
nextUp
public static float nextUp (float f)
Returns the floating-point value adjacent to 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:
- 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
Float#MIN_VALUE
Parameters | |
---|---|
f |
float : starting floating-point value |
Returns | |
---|---|
float |
The adjacent floating-point value closer to positive infinity. |
pow
public static 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,
- 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,
- 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,
- 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,
- 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,
- 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,
- 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,
- 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,
- 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 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.)
API Note:
- The special cases definitions of this method differ from the
special case definitions of the IEEE 754 recommended
pow
operation for ±1.0
raised to an infinite power. This method treats such cases as indeterminate and specifies a NaN is returned. The IEEE 754 specification treats the infinite power as a large integer (large-magnitude floating-point numbers are numerically integers, specifically even integers) and therefore specifies1.0
be returned.
Parameters | |
---|---|
a |
double : base. |
b |
double : the exponent. |
Returns | |
---|---|
double |
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 | |
---|---|
double |
a pseudorandom double greater than or equal
to 0.0 and less than 1.0 . |
See also:
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 |
double : a value. |
Returns | |
---|---|
double |
the closest floating-point value to a that is
equal to a mathematical integer. |
round
public static int round (float a)
Returns the closest int
to the argument, with ties
rounding to positive infinity.
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 ofInteger.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 ofInteger.MAX_VALUE
.
Parameters | |
---|---|
a |
float : a floating-point value to be rounded to an integer. |
Returns | |
---|---|
int |
the value of the argument rounded to the nearest
int value. |
See also:
round
public static long round (double a)
Returns the closest long
to the argument, with ties
rounding to positive infinity.
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 ofLong.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 ofLong.MAX_VALUE
.
Parameters | |
---|---|
a |
double : a floating-point value to be rounded to a
long . |
Returns | |
---|---|
long |
the value of the argument rounded to the nearest
long value. |
See also:
scalb
public static float scalb (float f, int scaleFactor)
Returns f
× 2scaleFactor
rounded as if performed by a single correctly rounded
floating-point multiply. 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:
- 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 |
float : number to be scaled by a power of two. |
scaleFactor |
int : power of 2 used to scale f |
Returns | |
---|---|
float |
f × 2scaleFactor |
scalb
public static double scalb (double d, int scaleFactor)
Returns d
× 2scaleFactor
rounded as if performed by a single correctly rounded
floating-point multiply. 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:
- 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 |
double : number to be scaled by a power of two. |
scaleFactor |
int : power of 2 used to scale d |
Returns | |
---|---|
double |
d × 2scaleFactor |
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 |
float : the floating-point value whose signum is to be returned |
Returns | |
---|---|
float |
the signum function of the argument |
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 |
double : the floating-point value whose signum is to be returned |
Returns | |
---|---|
double |
the signum function of the argument |
sin
public static 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 |
double : an angle, in radians. |
Returns | |
---|---|
double |
the sine of the argument. |
sinh
public static double sinh (double x)
Returns the hyperbolic sine of a double
value.
The hyperbolic sine of x is defined to be
(ex - e-x)/2
where e is 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 |
double : The number whose hyperbolic sine is to be returned. |
Returns | |
---|---|
double |
The hyperbolic sine of x . |
sqrt
public static 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.
double
value closest to
the true mathematical square root of the argument value.
Parameters | |
---|---|
a |
double : a value. |
Returns | |
---|---|
double |
the positive square root of a . |
subtractExact
public static int subtractExact (int x, int y)
Returns the difference of the arguments,
throwing an exception if the result overflows an int
.
Parameters | |
---|---|
x |
int : the first value |
y |
int : the second value to subtract from the first |
Returns | |
---|---|
int |
the result |
Throws | |
---|---|
ArithmeticException |
if the result overflows an int |
See also:
subtractExact
public static long subtractExact (long x, long y)
Returns the difference of the arguments,
throwing an exception if the result overflows a long
.
Parameters | |
---|---|
x |
long : the first value |
y |
long : the second value to subtract from the first |
Returns | |
---|---|
long |
the result |
Throws | |
---|---|
ArithmeticException |
if the result overflows a long |
See also:
tan
public static 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 |
double : an angle, in radians. |
Returns | |
---|---|
double |
the tangent of the argument. |
tanh
public static double tanh (double x)
Returns the hyperbolic tangent of a 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:
- 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 |
double : The number whose hyperbolic tangent is to be returned. |
Returns | |
---|---|
double |
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 |
double : an angle, in radians |
Returns | |
---|---|
double |
the measurement of the angle angrad
in degrees. |
toIntExact
public static int toIntExact (long value)
Returns the value of the long
argument, throwing an exception
if the value overflows an int
.
Parameters | |
---|---|
value |
long : the long value |
Returns | |
---|---|
int |
the argument as an int |
Throws | |
---|---|
ArithmeticException |
if the argument overflows an int |
See also:
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 |
double : an angle, in degrees |
Returns | |
---|---|
double |
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, unit in
the last place, 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 |
double : the floating-point value whose ulp is to be returned |
Returns | |
---|---|
double |
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, unit in
the last place, 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 |
float : the floating-point value whose ulp is to be returned |
Returns | |
---|---|
float |
the size of an ulp of the argument |
unsignedMultiplyHigh
public static long unsignedMultiplyHigh (long x, long y)
Returns as a long
the most significant 64 bits of the unsigned
128-bit product of two unsigned 64-bit factors.
Parameters | |
---|---|
x |
long : the first value |
y |
long : the second value |
Returns | |
---|---|
long |
the result |