math32

README

README

go-math32

• Float32 version of the standard go math package

Documentation

Overview

Package math32 provides basic constants and mathematical functions related to the float32 type.

This package does not guarantee bit-identical results across architectures.

Index

• Constants
• func Abs(x float32) float32
• func Acos(x float32) float32
• func Acosh(x float32) float32
• func Asin(x float32) float32
• func Asinh(x float32) float32
• func Atan(x float32) float32
• func Atan2(y, x float32) float32
• func Atanh(x float32) float32
• func Cbrt(x float32) float32
• func Ceil(x float32) float32
• func Copysign(x, y float32) float32
• func Cos(x float32) float32
• func Dim(x, y float32) float32
• func Erf(x float32) float32
• func Erfc(x float32) float32
• func Erfcinv(x float32) float32
• func Erfinv(x float32) float32
• func Exp(x float32) float32
• func Exp2(x float32) float32
• func Expm1(x float32) float32
• func Floor(x float32) float32
• func Frexp(f float32) (frac float32, exp int)
• func Gamma(x float32) float32
• func Inf(sign int) float32
• func IsInf(f float32, sign int) bool
• func IsNaN(f float32) (is bool)
• func Ldexp(frac float32, exp int) float32
• func Log(x float32) float32
• func Log1p(x float32) float32
• func Max(x, y float32) float32
• func Min(x, y float32) float32
• func Mod(x, y float32) float32
• func Modf(f float32) (int float32, frac float32)
• func NaN() float32
• func Pow(x, y float32) float32
• func Round(x float32) float32
• func RoundToEven(x float32) float32
• func Signbit(x float32) bool
• func Sin(x float32) float32
• func Sqrt(x float32) float32
• func Tan(x float32) float32
• func Trunc(x float32) float32

Constants

const (
	E   = math.E
	Pi  = math.Pi
	Phi = math.Phi

	Sqrt2   = math.Sqrt2
	SqrtE   = math.SqrtE
	SqrtPi  = math.SqrtPi
	SqrtPhi = math.SqrtPhi

	Ln2    = math.Ln2
	Log2E  = math.Log2E
	Ln10   = math.Ln10
	Log10E = math.Log10E
)

Mathematical constants, copied over from the math package for consistency between packages.

const (
	MaxFloat32             = math.MaxFloat32
	SmallestNonzeroFloat32 = math.SmallestNonzeroFloat32

	MaxFloat64             = math.MaxFloat64
	SmallestNonzeroFloat64 = math.SmallestNonzeroFloat64
)

Floating-point limit values. Max is the largest finite value representable by the type. SmallestNonzero is the smallest positive, non-zero value representable by the type.

Functions

func Abs

func Abs(x float32) float32

Abs returns the absolute value of x.

Special cases are:

Abs(±Inf) = +Inf
Abs(NaN) = NaN

func Acos

func Acos(x float32) float32

Acos returns the arccosine, in radians, of x.

Special case is:

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

func Acosh

func Acosh(x float32) float32

Acosh returns the inverse hyperbolic cosine of x.

Special cases are:

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

func Asin

func Asin(x float32) float32

Asin returns the arcsine, in radians, of x.

Special cases are:

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

func Asinh

func Asinh(x float32) float32

Asinh returns the inverse hyperbolic sine of x.

Special cases are:

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

func Atan

func Atan(x float32) float32

Atan returns the arctangent, in radians, of x.

Special cases are:

Atan(±0) = ±0
Atan(±Inf) = ±Pi/2

func Atan2

func Atan2(y, x float32) float32

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

func Atanh

func Atanh(x float32) float32

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

func Cbrt

func Cbrt(x float32) float32

Cbrt returns the cube root of x.

Special cases are:

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

func Ceil

func Ceil(x float32) float32

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

Special cases are:

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

func Copysign

func Copysign(x, y float32) float32

Copysign returns a value with the magnitude of x and the sign of y.

func Cos

func Cos(x float32) float32

Cos returns the cosine of the radian argument x.

Special cases are:

Cos(±Inf) = NaN
Cos(NaN) = NaN

func Dim

func Dim(x, y float32) float32

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

func Erf

func Erf(x float32) float32

Erf returns the error function of x.

Special cases are:

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

func Erfc

func Erfc(x float32) float32

Erfc returns the complementary error function of x.

Special cases are:

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

func Erfcinv

func Erfcinv(x float32) float32

Erfcinv returns the inverse of Erfc(x).

Special cases are:

Erfcinv(0) = +Inf
Erfcinv(2) = -Inf
Erfcinv(x) = NaN if x < 0 or x > 2
Erfcinv(NaN) = NaN

func Erfinv

func Erfinv(x float32) float32

Erfinv returns the inverse error function of x.

Special cases are:

Erfinv(1) = +Inf
Erfinv(-1) = -Inf
Erfinv(x) = NaN if x < -1 or x > 1
Erfinv(NaN) = NaN

func Exp

func Exp(x float32) float32

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.

func Exp2

func Exp2(x float32) float32

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

Special cases are the same as Exp.

func Expm1

func Expm1(x float32) float32

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.

func Floor

func Floor(x float32) float32

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

Special cases are:

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

func Frexp

func Frexp(f float32) (frac float32, 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

func Gamma(x float32) float32

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 Inf

func Inf(sign int) float32

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

func IsInf

func IsInf(f float32, 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

func IsNaN(f float32) (is bool)

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

func Ldexp

func Ldexp(frac float32, exp int) float32

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 Log

func Log(x float32) float32

Log returns the natural logarithm of x.

Special cases are:

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

func Log1p

func Log1p(x float32) float32

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 Max

func Max(x, y float32) float32

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

func Min(x, y float32) float32

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

func Mod(x, y float32) float32

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

func Modf

func Modf(f float32) (int float32, frac float32)

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

func NaN

func NaN() float32

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

func Pow

func Pow(x, y float32) float32

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

func Round

func Round(x float32) float32

Round returns the nearest integer, rounding half away from zero.

Special cases are:

Round(±0) = ±0
Round(±Inf) = ±Inf
Round(NaN) = NaN

func RoundToEven

func RoundToEven(x float32) float32

RoundToEven returns the nearest integer, rounding ties to even.

Special cases are:

RoundToEven(±0) = ±0
RoundToEven(±Inf) = ±Inf
RoundToEven(NaN) = NaN

func Signbit

func Signbit(x float32) bool

Signbit reports whether x is negative or negative zero.

func Sin

func Sin(x float32) float32

Sin returns the sine of the radian argument x.

Special cases are:

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

func Sqrt

func Sqrt(x float32) float32

Sqrt returns the square root of x.

Special cases are:

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

func Tan

func Tan(x float32) float32

Tan returns the tangent of the radian argument x.

Special cases are:

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

func Trunc

func Trunc(x float32) float32

Trunc returns the integer value of x.

Special cases are:

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