math

func Abs

1func Abs(x float64) float64

Abs returns the absolute value of x.

Special cases are:

Abs(±Inf) = +Inf
Abs(NaN) = NaN

1x := math.Abs(-2)
2fmt.Printf("%.1f\n", x)
3
4y := math.Abs(2)
5fmt.Printf("%.1f\n", y)

2.0
2.0

func Acos

1func Acos(x float64) float64

Acos returns the arccosine, in radians, of x.

Special case is:

Acos(x) = NaN if x < -1 or x > 1

1fmt.Printf("%.2f", math.Acos(1))

0.00

func Acosh

1func Acosh(x float64) float64

Acosh returns the inverse hyperbolic cosine of x.

Special cases are:

Acosh(+Inf) = +Inf
Acosh(x) = NaN if x < 1
Acosh(NaN) = NaN

1fmt.Printf("%.2f", math.Acosh(1))

0.00

func Asin

1func Asin(x float64) float64

Asin returns the arcsine, in radians, of x.

Special cases are:

Asin(±0) = ±0
Asin(x) = NaN if x < -1 or x > 1

1fmt.Printf("%.2f", math.Asin(0))

0.00

func Asinh

1func Asinh(x float64) float64

Asinh returns the inverse hyperbolic sine of x.

Special cases are:

Asinh(±0) = ±0
Asinh(±Inf) = ±Inf
Asinh(NaN) = NaN

1fmt.Printf("%.2f", math.Asinh(0))

0.00

func Atan

1func Atan(x float64) float64

Atan returns the arctangent, in radians, of x.

Special cases are:

Atan(±0) = ±0
Atan(±Inf) = ±Pi/2

1fmt.Printf("%.2f", math.Atan(0))

0.00

func Atan2

1func Atan2(y, x float64) float64

Atan2 returns the arc tangent of y/x, using the signs of the two to determine the quadrant of the return value.

Special cases are (in order):

Atan2(y, NaN) = NaN
Atan2(NaN, x) = NaN
Atan2(+0, x>=0) = +0
Atan2(-0, x>=0) = -0
Atan2(+0, x<=-0) = +Pi
Atan2(-0, x<=-0) = -Pi
Atan2(y>0, 0) = +Pi/2
Atan2(y<0, 0) = -Pi/2
Atan2(+Inf, +Inf) = +Pi/4
Atan2(-Inf, +Inf) = -Pi/4
Atan2(+Inf, -Inf) = 3Pi/4
Atan2(-Inf, -Inf) = -3Pi/4
Atan2(y, +Inf) = 0
Atan2(y>0, -Inf) = +Pi
Atan2(y<0, -Inf) = -Pi
Atan2(+Inf, x) = +Pi/2
Atan2(-Inf, x) = -Pi/2

1fmt.Printf("%.2f", math.Atan2(0, 0))

0.00

func Atanh

1func Atanh(x float64) float64

Atanh returns the inverse hyperbolic tangent of x.

Special cases are:

Atanh(1) = +Inf
Atanh(±0) = ±0
Atanh(-1) = -Inf
Atanh(x) = NaN if x < -1 or x > 1
Atanh(NaN) = NaN

1fmt.Printf("%.2f", math.Atanh(0))

0.00

func Cbrt

1func Cbrt(x float64) float64

Cbrt returns the cube root of x.

Special cases are:

Cbrt(±0) = ±0
Cbrt(±Inf) = ±Inf
Cbrt(NaN) = NaN

1fmt.Printf("%.2f\n", math.Cbrt(8))
2fmt.Printf("%.2f\n", math.Cbrt(27))

2.00
3.00

func Ceil

1func Ceil(x float64) float64

Ceil returns the least integer value greater than or equal to x.

Special cases are:

Ceil(±0) = ±0
Ceil(±Inf) = ±Inf
Ceil(NaN) = NaN

1c := math.Ceil(1.49)
2fmt.Printf("%.1f", c)

2.0

func Copysign

1func Copysign(f, sign float64) float64

Copysign returns a value with the magnitude of f and the sign of sign.

1fmt.Printf("%.2f", math.Copysign(3.2, -1))

-3.20

func Cos

1func Cos(x float64) float64

Cos returns the cosine of the radian argument x.

Special cases are:

Cos(±Inf) = NaN
Cos(NaN) = NaN

1fmt.Printf("%.2f", math.Cos(math.Pi/2))

0.00

func Cosh

1func Cosh(x float64) float64

Cosh returns the hyperbolic cosine of x.

Special cases are:

Cosh(±0) = 1
Cosh(±Inf) = +Inf
Cosh(NaN) = NaN

1fmt.Printf("%.2f", math.Cosh(0))

1.00

func Dim

1func Dim(x, y float64) float64

Dim returns the maximum of x-y or 0.

Special cases are:

Dim(+Inf, +Inf) = NaN
Dim(-Inf, -Inf) = NaN
Dim(x, NaN) = Dim(NaN, x) = NaN

1fmt.Printf("%.2f\n", math.Dim(4, -2))
2fmt.Printf("%.2f\n", math.Dim(-4, 2))

6.00
0.00

func Erf

1func Erf(x float64) float64

Erf returns the error function of x.

Special cases are:

Erf(+Inf) = 1
Erf(-Inf) = -1
Erf(NaN) = NaN

func Erfc

1func Erfc(x float64) float64

Erfc returns the complementary error function of x.

Special cases are:

Erfc(+Inf) = 0
Erfc(-Inf) = 2
Erfc(NaN) = NaN

func Exp

1func Exp(x float64) float64

Exp returns e**x, the base-e exponential of x.

Special cases are:

Exp(+Inf) = +Inf
Exp(NaN) = NaN

Very large values overflow to 0 or +Inf. Very small values underflow to 1.

1fmt.Printf("%.2f\n", math.Exp(1))
2fmt.Printf("%.2f\n", math.Exp(2))
3fmt.Printf("%.2f\n", math.Exp(-1))

2.72
7.39
0.37

func Exp2

1func Exp2(x float64) float64

Exp2 returns 2**x, the base-2 exponential of x.

Special cases are the same as Exp.

1fmt.Printf("%.2f\n", math.Exp2(1))
2fmt.Printf("%.2f\n", math.Exp2(-3))

2.00
0.12

func Expm1

1func Expm1(x float64) float64

Expm1 returns e**x - 1, the base-e exponential of x minus 1. It is more accurate than Exp(x) - 1 when x is near zero.

Special cases are:

Expm1(+Inf) = +Inf
Expm1(-Inf) = -1
Expm1(NaN) = NaN

Very large values overflow to -1 or +Inf.

1fmt.Printf("%.6f\n", math.Expm1(0.01))
2fmt.Printf("%.6f\n", math.Expm1(-1))

0.010050
-0.632121

func Float32bits

1func Float32bits(f float32) uint32

Float32bits returns the IEEE 754 binary representation of f, with the sign bit of f and the result in the same bit position. Float32bits(Float32frombits(x)) == x.

func Float32frombits

1func Float32frombits(b uint32) float32

Float32frombits returns the floating-point number corresponding to the IEEE 754 binary representation b, with the sign bit of b and the result in the same bit position. Float32frombits(Float32bits(x)) == x.

func Float64bits

1func Float64bits(f float64) uint64

Float64bits returns the IEEE 754 binary representation of f, with the sign bit of f and the result in the same bit position, and Float64bits(Float64frombits(x)) == x.

func Float64frombits

1func Float64frombits(b uint64) float64

Float64frombits returns the floating-point number corresponding to the IEEE 754 binary representation b, with the sign bit of b and the result in the same bit position. Float64frombits(Float64bits(x)) == x.

func Floor

1func Floor(x float64) float64

Floor returns the greatest integer value less than or equal to x.

Special cases are:

Floor(±0) = ±0
Floor(±Inf) = ±Inf
Floor(NaN) = NaN

1c := math.Floor(1.51)
2fmt.Printf("%.1f", c)

1.0

func Frexp

1func Frexp(f float64) (frac float64, exp int)

Frexp breaks f into a normalized fraction and an integral power of two. It returns frac and exp satisfying f == frac × 2**exp, with the absolute value of frac in the interval [½, 1).

Special cases are:

Frexp(±0) = ±0, 0
Frexp(±Inf) = ±Inf, 0
Frexp(NaN) = NaN, 0

func Gamma

1func Gamma(x float64) float64

Gamma returns the Gamma function of x.

Special cases are:

Gamma(+Inf) = +Inf
Gamma(+0) = +Inf
Gamma(-0) = -Inf
Gamma(x) = NaN for integer x < 0
Gamma(-Inf) = NaN
Gamma(NaN) = NaN

func Hypot

1func Hypot(p, q float64) float64

Hypot returns Sqrt(p*p + q*q), taking care to avoid unnecessary overflow and underflow.

Special cases are:

Hypot(±Inf, q) = +Inf
Hypot(p, ±Inf) = +Inf
Hypot(NaN, q) = NaN
Hypot(p, NaN) = NaN

func Ilogb

1func Ilogb(x float64) int

Ilogb returns the binary exponent of x as an integer.

Special cases are:

Ilogb(±Inf) = MaxInt32
Ilogb(0) = MinInt32
Ilogb(NaN) = MaxInt32

func Inf

1func Inf(sign int) float64

Inf returns positive infinity if sign >= 0, negative infinity if sign < 0.

func IsInf

1func IsInf(f float64, sign int) bool

IsInf reports whether f is an infinity, according to sign. If sign > 0, IsInf reports whether f is positive infinity. If sign < 0, IsInf reports whether f is negative infinity. If sign == 0, IsInf reports whether f is either infinity.

func IsNaN

1func IsNaN(f float64) (is bool)

IsNaN reports whether f is an IEEE 754 “not-a-number” value.

func J0

1func J0(x float64) float64

J0 returns the order-zero Bessel function of the first kind.

Special cases are:

J0(±Inf) = 0
J0(0) = 1
J0(NaN) = NaN

func J1

1func J1(x float64) float64

J1 returns the order-one Bessel function of the first kind.

Special cases are:

J1(±Inf) = 0
J1(NaN) = NaN

func Jn

1func Jn(n int, x float64) float64

Jn returns the order-n Bessel function of the first kind.

Special cases are:

Jn(n, ±Inf) = 0
Jn(n, NaN) = NaN

func Ldexp

1func Ldexp(frac float64, exp int) float64

Ldexp is the inverse of Frexp. It returns frac × 2**exp.

Special cases are:

Ldexp(±0, exp) = ±0
Ldexp(±Inf, exp) = ±Inf
Ldexp(NaN, exp) = NaN

func Lgamma

1func Lgamma(x float64) (lgamma float64, sign int)

Lgamma returns the natural logarithm and sign (-1 or +1) of Gamma(x).

Special cases are:

Lgamma(+Inf) = +Inf
Lgamma(0) = +Inf
Lgamma(-integer) = +Inf
Lgamma(-Inf) = -Inf
Lgamma(NaN) = NaN

func Log

1func Log(x float64) float64

Log returns the natural logarithm of x.

Special cases are:

Log(+Inf) = +Inf
Log(0) = -Inf
Log(x < 0) = NaN
Log(NaN) = NaN

1x := math.Log(1)
2fmt.Printf("%.1f\n", x)
3
4y := math.Log(2.7183)
5fmt.Printf("%.1f\n", y)

0.0
1.0

func Log10

1func Log10(x float64) float64

Log10 returns the decimal logarithm of x. The special cases are the same as for Log.

1fmt.Printf("%.1f", math.Log10(100))

2.0

func Log1p

1func Log1p(x float64) float64

Log1p returns the natural logarithm of 1 plus its argument x. It is more accurate than Log(1 + x) when x is near zero.

Special cases are:

Log1p(+Inf) = +Inf
Log1p(±0) = ±0
Log1p(-1) = -Inf
Log1p(x < -1) = NaN
Log1p(NaN) = NaN

func Log2

1func Log2(x float64) float64

Log2 returns the binary logarithm of x. The special cases are the same as for Log.

1fmt.Printf("%.1f", math.Log2(256))

8.0

func Logb

1func Logb(x float64) float64

Logb returns the binary exponent of x.

Special cases are:

Logb(±Inf) = +Inf
Logb(0) = -Inf
Logb(NaN) = NaN

func Max

1func Max(x, y float64) float64

Max returns the larger of x or y.

Special cases are:

Max(x, +Inf) = Max(+Inf, x) = +Inf
Max(x, NaN) = Max(NaN, x) = NaN
Max(+0, ±0) = Max(±0, +0) = +0
Max(-0, -0) = -0

func Min

1func Min(x, y float64) float64

Min returns the smaller of x or y.

Special cases are:

Min(x, -Inf) = Min(-Inf, x) = -Inf
Min(x, NaN) = Min(NaN, x) = NaN
Min(-0, ±0) = Min(±0, -0) = -0

func Mod

1func Mod(x, y float64) float64

Mod returns the floating-point remainder of x/y. The magnitude of the result is less than y and its sign agrees with that of x.

Special cases are:

Mod(±Inf, y) = NaN
Mod(NaN, y) = NaN
Mod(x, 0) = NaN
Mod(x, ±Inf) = x
Mod(x, NaN) = NaN

1c := math.Mod(7, 4)
2fmt.Printf("%.1f", c)

3.0

func Modf

1func Modf(f float64) (int float64, frac float64)

Modf returns integer and fractional floating-point numbers that sum to f. Both values have the same sign as f.

Special cases are:

Modf(±Inf) = ±Inf, NaN
Modf(NaN) = NaN, NaN

1int, frac := math.Modf(3.14)
2fmt.Printf("%.2f, %.2f\n", int, frac)
3
4int, frac = math.Modf(-2.71)
5fmt.Printf("%.2f, %.2f\n", int, frac)

3.00, 0.14
-2.00, -0.71

func NaN

1func NaN() float64

NaN returns an IEEE 754 “not-a-number” value.

func Nextafter

1func Nextafter(x, y float64) (r float64)

Nextafter returns the next representable float64 value after x towards y.

Special cases are:

Nextafter(x, x)   = x
Nextafter(NaN, y) = NaN
Nextafter(x, NaN) = NaN

func Pow

1func Pow(x, y float64) float64

Pow returns x**y, the base-x exponential of y.

Special cases are (in order):

Pow(x, ±0) = 1 for any x
Pow(1, y) = 1 for any y
Pow(x, 1) = x for any x
Pow(NaN, y) = NaN
Pow(x, NaN) = NaN
Pow(±0, y) = ±Inf for y an odd integer < 0
Pow(±0, -Inf) = +Inf
Pow(±0, +Inf) = +0
Pow(±0, y) = +Inf for finite y < 0 and not an odd integer
Pow(±0, y) = ±0 for y an odd integer > 0
Pow(±0, y) = +0 for finite y > 0 and not an odd integer
Pow(-1, ±Inf) = 1
Pow(x, +Inf) = +Inf for |x| > 1
Pow(x, -Inf) = +0 for |x| > 1
Pow(x, +Inf) = +0 for |x| < 1
Pow(x, -Inf) = +Inf for |x| < 1
Pow(+Inf, y) = +Inf for y > 0
Pow(+Inf, y) = +0 for y < 0
Pow(-Inf, y) = Pow(-0, -y)
Pow(x, y) = NaN for finite x < 0 and finite non-integer y

1c := math.Pow(2, 3)
2fmt.Printf("%.1f", c)

8.0

func Pow10

1func Pow10(n int) float64

Pow10 returns 10**n, the base-10 exponential of n.

Special cases are:

Pow10(n) =    0 for n < -323
Pow10(n) = +Inf for n > 308

1c := math.Pow10(2)
2fmt.Printf("%.1f", c)

100.0

func Remainder

1func Remainder(x, y float64) float64

Remainder returns the IEEE 754 floating-point remainder of x/y.

Special cases are:

Remainder(±Inf, y) = NaN
Remainder(NaN, y) = NaN
Remainder(x, 0) = NaN
Remainder(x, ±Inf) = x
Remainder(x, NaN) = NaN

1fmt.Printf("%.1f", math.Remainder(100, 30))

10.0

func Signbit

1func Signbit(x float64) bool

Signbit reports whether x is negative or negative zero.

func Sin

1func Sin(x float64) float64

Sin returns the sine of the radian argument x.

Special cases are:

Sin(±0) = ±0
Sin(±Inf) = NaN
Sin(NaN) = NaN

1fmt.Printf("%.2f", math.Sin(math.Pi))

0.00

func Sincos

1func Sincos(x float64) (sin, cos float64)

Sincos returns Sin(x), Cos(x).

Special cases are:

Sincos(±0) = ±0, 1
Sincos(±Inf) = NaN, NaN
Sincos(NaN) = NaN, NaN

1sin, cos := math.Sincos(0)
2fmt.Printf("%.2f, %.2f", sin, cos)

0.00, 1.00

func Sinh

1func Sinh(x float64) float64

Sinh returns the hyperbolic sine of x.

Special cases are:

Sinh(±0) = ±0
Sinh(±Inf) = ±Inf
Sinh(NaN) = NaN

1fmt.Printf("%.2f", math.Sinh(0))

0.00

func Sqrt

1func Sqrt(x float64) float64

Sqrt returns the square root of x.

Special cases are:

Sqrt(+Inf) = +Inf
Sqrt(±0) = ±0
Sqrt(x < 0) = NaN
Sqrt(NaN) = NaN

1const (
2	a	= 3
3	b	= 4
4)
5c := math.Sqrt(a*a + b*b)
6fmt.Printf("%.1f", c)

5.0

func Tan

1func Tan(x float64) float64

Tan returns the tangent of the radian argument x.

Special cases are:

Tan(±0) = ±0
Tan(±Inf) = NaN
Tan(NaN) = NaN

1fmt.Printf("%.2f", math.Tan(0))

0.00

func Tanh

1func Tanh(x float64) float64

Tanh returns the hyperbolic tangent of x.

Special cases are:

Tanh(±0) = ±0
Tanh(±Inf) = ±1
Tanh(NaN) = NaN

1fmt.Printf("%.2f", math.Tanh(0))

0.00

func Trunc

1func Trunc(x float64) float64

Trunc returns the integer value of x.

Special cases are:

Trunc(±0) = ±0
Trunc(±Inf) = ±Inf
Trunc(NaN) = NaN

1fmt.Printf("%.2f\n", math.Trunc(math.Pi))
2fmt.Printf("%.2f\n", math.Trunc(-1.2345))

3.00
-1.00

func Y0

1func Y0(x float64) float64

Y0 returns the order-zero Bessel function of the second kind.

Special cases are:

Y0(+Inf) = 0
Y0(0) = -Inf
Y0(x < 0) = NaN
Y0(NaN) = NaN

func Y1

1func Y1(x float64) float64

Y1 returns the order-one Bessel function of the second kind.

Special cases are:

Y1(+Inf) = 0
Y1(0) = -Inf
Y1(x < 0) = NaN
Y1(NaN) = NaN

func Yn

1func Yn(n int, x float64) float64

Yn returns the order-n Bessel function of the second kind.

Special cases are:

Yn(n, +Inf) = 0
Yn(n ≥ 0, 0) = -Inf
Yn(n < 0, 0) = +Inf if n is odd, -Inf if n is even
Yn(n, x < 0) = NaN
Yn(n, NaN) = NaN