math

package
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Published: Dec 22, 2024 License: Apache-2.0 Imports: 4 Imported by: 0

Documentation

Overview

Package math provides generic arithmetic functions

It intentionally does not support floating point types, as that would require reflect in generic code, for special handling of NaN, ±∞ and -0. Use the standard library math package instead.

Index

Constants

View Source
const (
	E   = 2.71828182845904523536028747135266249775724709369995957496696763 // https://oeis.org/A001113
	Pi  = 3.14159265358979323846264338327950288419716939937510582097494459 // https://oeis.org/A000796
	Phi = 1.61803398874989484820458683436563811772030917980576286213544862 // https://oeis.org/A001622

	Sqrt2   = 1.41421356237309504880168872420969807856967187537694807317667974 // https://oeis.org/A002193
	SqrtE   = 1.64872127070012814684865078781416357165377610071014801157507931 // https://oeis.org/A019774
	SqrtPi  = 1.77245385090551602729816748334114518279754945612238712821380779 // https://oeis.org/A002161
	SqrtPhi = 1.27201964951406896425242246173749149171560804184009624861664038 // https://oeis.org/A139339

	Ln2    = 0.693147180559945309417232121458176568075500134360255254120680009 // https://oeis.org/A002162
	Log2E  = 1 / Ln2
	Ln10   = 2.30258509299404568401799145468436420760110148862877297603332790 // https://oeis.org/A002392
	Log10E = 1 / Ln10
)

Mathematical constants.

View Source
const (
	MaxFloat32             = 0x1p127 * (1 + (1 - 0x1p-23)) // 3.40282346638528859811704183484516925440e+38
	SmallestNonzeroFloat32 = 0x1p-126 * 0x1p-23            // 1.401298464324817070923729583289916131280e-45

	MaxFloat64             = 0x1p1023 * (1 + (1 - 0x1p-52)) // 1.79769313486231570814527423731704356798070e+308
	SmallestNonzeroFloat64 = 0x1p-1022 * 0x1p-52            // 4.9406564584124654417656879286822137236505980e-324
)

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.

View Source
const (
	MaxInt    = 1<<(intSize-1) - 1  // MaxInt32 or MaxInt64 depending on intSize.
	MinInt    = -1 << (intSize - 1) // MinInt32 or MinInt64 depending on intSize.
	MaxInt8   = 1<<7 - 1            // 127
	MinInt8   = -1 << 7             // -128
	MaxInt16  = 1<<15 - 1           // 32767
	MinInt16  = -1 << 15            // -32768
	MaxInt32  = 1<<31 - 1           // 2147483647
	MinInt32  = -1 << 31            // -2147483648
	MaxInt64  = 1<<63 - 1           // 9223372036854775807
	MinInt64  = -1 << 63            // -9223372036854775808
	MaxUint   = 1<<intSize - 1      // MaxUint32 or MaxUint64 depending on intSize.
	MaxUint8  = 1<<8 - 1            // 255
	MaxUint16 = 1<<16 - 1           // 65535
	MaxUint32 = 1<<32 - 1           // 4294967295
	MaxUint64 = 1<<64 - 1           // 18446744073709551615
)

Integer limit values.

Variables

This section is empty.

Functions

func Abs

func Abs[T constraints.Signed](v T) T

Abs returns the absolute value of v.

func ChineseRemainder

func ChineseRemainder[T constraints.Integer](a, m, b, n T) (x, M T, ok bool)

ChineseRemainder solves the Chinese Remainder Theorem. The return values satisfy

x = a (mod m)
x = b (mod n)
0 <= x < LCM(m, n) = M

If such an x exists. Otherwise it returns a, m, false.

It panics if m==0 or n==0.

func ChineseRemainderBig

func ChineseRemainderBig(a, m, b, n *big.Int) bool

ChineseRemainderBig solves the Chinese Remainder Theorem for big.Int. It calculates x such that

x = a (mod m)
x = b (mod n)
0 <= x < LCM(m, n) = M

If such an x exists, and stores x and M in a and m. Otherwise, it returns false and leaves the inputs unmodified.

It panics if m or n is zero.

func Cmp

func Cmp[T TotallyOrdered](a, b T) int

Cmp returns -1, 0 and 1, if a < b, a == b and a > b, respectively.

func Cramer2

func Cramer2[T constraints.Integer](a, b, c [2]T) (x [2]T, ok bool)

Cramer2 solves the linear equation x₀•a+x₁•b=c. It returns [0, 0], false, if there is no unique integer solution.

func Cramer3

func Cramer3[T constraints.Integer](a, b, c, d [3]T) (x [3]T, ok bool)

Cramer3 solves the linear equation x₀•a+x₁•b+x₂•c=d. It returns [0, 0, 0], false, if there is no unique integer solutions.

func Digits

func Digits[T constraints.Integer](n T) int

Digits returns the number of decimal digits of the absolute value of n.

func Div

func Div[T constraints.Integer](a, b T) T

Div returns the quotient a/b for b != 0. Div implements Euclidean division; see DivMod for details.

func DivMod

func DivMod[T constraints.Integer](a, b T) (q, r T)

DivMod returns p, q such that a = b•q+r, with 0≤r<|b|. It panics if b is 0.

func GCD

func GCD[T constraints.Integer](a, b T) (z, x, y T)

GCD returns z, x, y, such that gcd(a, b) == z == a*x+b*y.

a and b may be positive, zero or negative.

If a == b == 0, GCD sets z = x = y = 0.

If a == 0 and b != 0, GCD sets z = |b|, x = 0, y = sign(b) * 1.

If a != 0 and b == 0, GCD sets z = |a|, x = sign(a) * 1, y = 0.

func LCM

func LCM[T constraints.Integer](a, b T) T

LCM returns the least common multiple of a and b.

func Log10

func Log10[T constraints.Integer](n T) int

Log10 returns the base-10 logarithm of n, rounded down. If n is not positive, Log10 panics.

func Max

func Max[T TotallyOrdered](a, b T) T

Max returns the maximum of a and b.

func Min

func Min[T TotallyOrdered](a, b T) T

Max returns the minimum of a and b.

func Mod

func Mod[T constraints.Integer](a, b T) T

Mod returns the modulus a%b for b != 0. Mod implements Euclidean division; see DivMod for details.

func Pow10

func Pow10(n int) uint64

Pow10 returns 10^n. It panics, if n is negative or the result would overflow.

func Sgn

func Sgn[T constraints.Signed](v T) T

Sgn returns -1, 0, 1 if v < 0, v == 0, v > 0, respectively.

Types

type TotallyOrdered

type TotallyOrdered interface {
	constraints.Integer | ~string
}

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