From 82ba818ff456bcd6d56a06226e3f27e98fbb55c3 Mon Sep 17 00:00:00 2001 From: Craig Jennings Date: Thu, 14 Aug 2025 22:58:58 -0500 Subject: removing all downloaded devdocs files --- devdocs/go/math%2Frand%2Fv2%2Findex.html | 278 ------------------------------- 1 file changed, 278 deletions(-) delete mode 100644 devdocs/go/math%2Frand%2Fv2%2Findex.html (limited to 'devdocs/go/math%2Frand%2Fv2%2Findex.html') diff --git a/devdocs/go/math%2Frand%2Fv2%2Findex.html b/devdocs/go/math%2Frand%2Fv2%2Findex.html deleted file mode 100644 index 79488bd92..000000000 --- a/devdocs/go/math%2Frand%2Fv2%2Findex.html +++ /dev/null @@ -1,278 +0,0 @@ -

Package rand

Overview

Package rand implements pseudo-random number generators suitable for tasks such as simulation, but it should not be used for security-sensitive work.

-

Random numbers are generated by a Source, usually wrapped in a Rand. Both types should be used by a single goroutine at a time: sharing among multiple goroutines requires some kind of synchronization.

-

Top-level functions, such as Float64 and Int, are safe for concurrent use by multiple goroutines.

-

This package's outputs might be easily predictable regardless of how it's seeded. For random numbers suitable for security-sensitive work, see the crypto/rand package.

Example -

Code:

-answers := []string{
-    "It is certain",
-    "It is decidedly so",
-    "Without a doubt",
-    "Yes definitely",
-    "You may rely on it",
-    "As I see it yes",
-    "Most likely",
-    "Outlook good",
-    "Yes",
-    "Signs point to yes",
-    "Reply hazy try again",
-    "Ask again later",
-    "Better not tell you now",
-    "Cannot predict now",
-    "Concentrate and ask again",
-    "Don't count on it",
-    "My reply is no",
-    "My sources say no",
-    "Outlook not so good",
-    "Very doubtful",
-}
-fmt.Println("Magic 8-Ball says:", answers[rand.IntN(len(answers))])
-

Example (Rand) -

This example shows the use of each of the methods on a *Rand. The use of the global functions is the same, without the receiver.

Code:

// Create and seed the generator.
-// Typically a non-fixed seed should be used, such as Uint64(), Uint64().
-// Using a fixed seed will produce the same output on every run.
-r := rand.New(rand.NewPCG(1, 2))
-
-// The tabwriter here helps us generate aligned output.
-w := tabwriter.NewWriter(os.Stdout, 1, 1, 1, ' ', 0)
-defer w.Flush()
-show := func(name string, v1, v2, v3 any) {
-    fmt.Fprintf(w, "%s\t%v\t%v\t%v\n", name, v1, v2, v3)
-}
-
-// Float32 and Float64 values are in [0, 1).
-show("Float32", r.Float32(), r.Float32(), r.Float32())
-show("Float64", r.Float64(), r.Float64(), r.Float64())
-
-// ExpFloat64 values have an average of 1 but decay exponentially.
-show("ExpFloat64", r.ExpFloat64(), r.ExpFloat64(), r.ExpFloat64())
-
-// NormFloat64 values have an average of 0 and a standard deviation of 1.
-show("NormFloat64", r.NormFloat64(), r.NormFloat64(), r.NormFloat64())
-
-// Int32, Int64, and Uint32 generate values of the given width.
-// The Int method (not shown) is like either Int32 or Int64
-// depending on the size of 'int'.
-show("Int32", r.Int32(), r.Int32(), r.Int32())
-show("Int64", r.Int64(), r.Int64(), r.Int64())
-show("Uint32", r.Uint32(), r.Uint32(), r.Uint32())
-
-// IntN, Int32N, and Int64N limit their output to be < n.
-// They do so more carefully than using r.Int()%n.
-show("IntN(10)", r.IntN(10), r.IntN(10), r.IntN(10))
-show("Int32N(10)", r.Int32N(10), r.Int32N(10), r.Int32N(10))
-show("Int64N(10)", r.Int64N(10), r.Int64N(10), r.Int64N(10))
-
-// Perm generates a random permutation of the numbers [0, n).
-show("Perm", r.Perm(5), r.Perm(5), r.Perm(5))
-

Output:

Float32     0.95955694          0.8076733            0.8135684
-Float64     0.4297927436037299  0.797802349388613    0.3883664855410056
-ExpFloat64  0.43463410545541104 0.5513632046504593   0.7426404617374481
-NormFloat64 -0.9303318111676635 -0.04750789419852852 0.22248301107582735
-Int32       2020777787          260808523            851126509
-Int64       5231057920893523323 4257872588489500903  158397175702351138
-Uint32      314478343           1418758728           208955345
-IntN(10)    6                   2                    0
-Int32N(10)  3                   7                    7
-Int64N(10)  8                   9                    4
-Perm        [0 3 1 4 2]         [4 1 2 0 3]          [4 3 2 0 1]
-

Index

Examples

Package
IntN
N
Perm
Shuffle
Shuffle (SlicesInUnison)
Package (Rand)

Package files

chacha8.go exp.go normal.go pcg.go rand.go zipf.go

func ExpFloat64 1.22 

func ExpFloat64() float64

ExpFloat64 returns an exponentially distributed float64 in the range (0, +math.MaxFloat64] with an exponential distribution whose rate parameter (lambda) is 1 and whose mean is 1/lambda (1) from the default Source. To produce a distribution with a different rate parameter, callers can adjust the output using:

-
sample = ExpFloat64() / desiredRateParameter
-

func Float32 1.22 

func Float32() float32

Float32 returns, as a float32, a pseudo-random number in the half-open interval [0.0,1.0) from the default Source.

-

func Float64 1.22 

func Float64() float64

Float64 returns, as a float64, a pseudo-random number in the half-open interval [0.0,1.0) from the default Source.

-

func Int 1.22 

func Int() int

Int returns a non-negative pseudo-random int from the default Source.

-

func Int32 1.22 

func Int32() int32

Int32 returns a non-negative pseudo-random 31-bit integer as an int32 from the default Source.

-

func Int32N 1.22 

func Int32N(n int32) int32

Int32N returns, as an int32, a pseudo-random number in the half-open interval [0,n) from the default Source. It panics if n <= 0.

-

func Int64 1.22 

func Int64() int64

Int64 returns a non-negative pseudo-random 63-bit integer as an int64 from the default Source.

-

func Int64N 1.22 

func Int64N(n int64) int64

Int64N returns, as an int64, a pseudo-random number in the half-open interval [0,n) from the default Source. It panics if n <= 0.

-

func IntN 1.22 

func IntN(n int) int

IntN returns, as an int, a pseudo-random number in the half-open interval [0,n) from the default Source. It panics if n <= 0.

Example -

Code:

-fmt.Println(rand.IntN(100))
-fmt.Println(rand.IntN(100))
-fmt.Println(rand.IntN(100))
-

func N 

func N[Int intType](n Int) Int

N returns a pseudo-random number in the half-open interval [0,n) from the default Source. The type parameter Int can be any integer type. It panics if n <= 0.

Example -

Code:

-// Print an int64 in the half-open interval [0, 100).
-fmt.Println(rand.N(int64(100)))
-
-// Sleep for a random duration between 0 and 100 milliseconds.
-time.Sleep(rand.N(100 * time.Millisecond))
-

func NormFloat64 1.22 

func NormFloat64() float64

NormFloat64 returns a normally distributed float64 in the range [-math.MaxFloat64, +math.MaxFloat64] with standard normal distribution (mean = 0, stddev = 1) from the default Source. To produce a different normal distribution, callers can adjust the output using:

-
sample = NormFloat64() * desiredStdDev + desiredMean
-

func Perm 1.22 

func Perm(n int) []int

Perm returns, as a slice of n ints, a pseudo-random permutation of the integers in the half-open interval [0,n) from the default Source.

Example -

Code:

for _, value := range rand.Perm(3) {
-    fmt.Println(value)
-}
-
-

Output:

1
-2
-0
-

func Shuffle 1.22 

func Shuffle(n int, swap func(i, j int))

Shuffle pseudo-randomizes the order of elements using the default Source. n is the number of elements. Shuffle panics if n < 0. swap swaps the elements with indexes i and j.

Example -

Code:

-words := strings.Fields("ink runs from the corners of my mouth")
-rand.Shuffle(len(words), func(i, j int) {
-    words[i], words[j] = words[j], words[i]
-})
-fmt.Println(words)
-

Example (SlicesInUnison) -

Code:

-numbers := []byte("12345")
-letters := []byte("ABCDE")
-// Shuffle numbers, swapping corresponding entries in letters at the same time.
-rand.Shuffle(len(numbers), func(i, j int) {
-    numbers[i], numbers[j] = numbers[j], numbers[i]
-    letters[i], letters[j] = letters[j], letters[i]
-})
-for i := range numbers {
-    fmt.Printf("%c: %c\n", letters[i], numbers[i])
-}
-

func Uint32 1.22 

func Uint32() uint32

Uint32 returns a pseudo-random 32-bit value as a uint32 from the default Source.

-

func Uint32N 1.22 

func Uint32N(n uint32) uint32

Uint32N returns, as a uint32, a pseudo-random number in the half-open interval [0,n) from the default Source. It panics if n <= 0.

-

func Uint64 1.22 

func Uint64() uint64

Uint64 returns a pseudo-random 64-bit value as a uint64 from the default Source.

-

func Uint64N 1.22 

func Uint64N(n uint64) uint64

Uint64N returns, as a uint64, a pseudo-random number in the half-open interval [0,n) from the default Source. It panics if n <= 0.

-

func UintN 1.22 

func UintN(n uint) uint

UintN returns, as a uint, a pseudo-random number in the half-open interval [0,n) from the default Source. It panics if n <= 0.

-

type ChaCha8 1.22

A ChaCha8 is a ChaCha8-based cryptographically strong random number generator.

-
type ChaCha8 struct {
-    // contains filtered or unexported fields
-}
-

func NewChaCha8 1.22 

func NewChaCha8(seed [32]byte) *ChaCha8

NewChaCha8 returns a new ChaCha8 seeded with the given seed.

-

func (*ChaCha8) MarshalBinary 1.22 

func (c *ChaCha8) MarshalBinary() ([]byte, error)

MarshalBinary implements the encoding.BinaryMarshaler interface.

-

func (*ChaCha8) Seed 1.22 

func (c *ChaCha8) Seed(seed [32]byte)

Seed resets the ChaCha8 to behave the same way as NewChaCha8(seed).

-

func (*ChaCha8) Uint64 1.22 

func (c *ChaCha8) Uint64() uint64

Uint64 returns a uniformly distributed random uint64 value.

-

func (*ChaCha8) UnmarshalBinary 1.22 

func (c *ChaCha8) UnmarshalBinary(data []byte) error

UnmarshalBinary implements the encoding.BinaryUnmarshaler interface.

-

type PCG 1.22

A PCG is a PCG generator with 128 bits of internal state. A zero PCG is equivalent to NewPCG(0, 0).

-
type PCG struct {
-    // contains filtered or unexported fields
-}
-

func NewPCG 1.22 

func NewPCG(seed1, seed2 uint64) *PCG

NewPCG returns a new PCG seeded with the given values.

-

func (*PCG) MarshalBinary 1.22 

func (p *PCG) MarshalBinary() ([]byte, error)

MarshalBinary implements the encoding.BinaryMarshaler interface.

-

func (*PCG) Seed 1.22 

func (p *PCG) Seed(seed1, seed2 uint64)

Seed resets the PCG to behave the same way as NewPCG(seed1, seed2).

-

func (*PCG) Uint64 1.22 

func (p *PCG) Uint64() uint64

Uint64 return a uniformly-distributed random uint64 value.

-

func (*PCG) UnmarshalBinary 1.22 

func (p *PCG) UnmarshalBinary(data []byte) error

UnmarshalBinary implements the encoding.BinaryUnmarshaler interface.

-

type Rand 1.22

A Rand is a source of random numbers.

-
type Rand struct {
-    // contains filtered or unexported fields
-}
-

func New 1.22 

func New(src Source) *Rand

New returns a new Rand that uses random values from src to generate other random values.

-

func (*Rand) ExpFloat64 1.22 

func (r *Rand) ExpFloat64() float64

ExpFloat64 returns an exponentially distributed float64 in the range (0, +math.MaxFloat64] with an exponential distribution whose rate parameter (lambda) is 1 and whose mean is 1/lambda (1). To produce a distribution with a different rate parameter, callers can adjust the output using:

-
sample = ExpFloat64() / desiredRateParameter
-

func (*Rand) Float32 1.22 

func (r *Rand) Float32() float32

Float32 returns, as a float32, a pseudo-random number in the half-open interval [0.0,1.0).

-

func (*Rand) Float64 1.22 

func (r *Rand) Float64() float64

Float64 returns, as a float64, a pseudo-random number in the half-open interval [0.0,1.0).

-

func (*Rand) Int 1.22 

func (r *Rand) Int() int

Int returns a non-negative pseudo-random int.

-

func (*Rand) Int32 1.22 

func (r *Rand) Int32() int32

Int32 returns a non-negative pseudo-random 31-bit integer as an int32.

-

func (*Rand) Int32N 1.22 

func (r *Rand) Int32N(n int32) int32

Int32N returns, as an int32, a non-negative pseudo-random number in the half-open interval [0,n). It panics if n <= 0.

-

func (*Rand) Int64 1.22 

func (r *Rand) Int64() int64

Int64 returns a non-negative pseudo-random 63-bit integer as an int64.

-

func (*Rand) Int64N 1.22 

func (r *Rand) Int64N(n int64) int64

Int64N returns, as an int64, a non-negative pseudo-random number in the half-open interval [0,n). It panics if n <= 0.

-

func (*Rand) IntN 1.22 

func (r *Rand) IntN(n int) int

IntN returns, as an int, a non-negative pseudo-random number in the half-open interval [0,n). It panics if n <= 0.

-

func (*Rand) NormFloat64 1.22 

func (r *Rand) NormFloat64() float64

NormFloat64 returns a normally distributed float64 in the range -math.MaxFloat64 through +math.MaxFloat64 inclusive, with standard normal distribution (mean = 0, stddev = 1). To produce a different normal distribution, callers can adjust the output using:

-
sample = NormFloat64() * desiredStdDev + desiredMean
-

func (*Rand) Perm 1.22 

func (r *Rand) Perm(n int) []int

Perm returns, as a slice of n ints, a pseudo-random permutation of the integers in the half-open interval [0,n).

-

func (*Rand) Shuffle 1.22 

func (r *Rand) Shuffle(n int, swap func(i, j int))

Shuffle pseudo-randomizes the order of elements. n is the number of elements. Shuffle panics if n < 0. swap swaps the elements with indexes i and j.

-

func (*Rand) Uint32 1.22 

func (r *Rand) Uint32() uint32

Uint32 returns a pseudo-random 32-bit value as a uint32.

-

func (*Rand) Uint32N 1.22 

func (r *Rand) Uint32N(n uint32) uint32

Uint32N returns, as a uint32, a non-negative pseudo-random number in the half-open interval [0,n). It panics if n == 0.

-

func (*Rand) Uint64 1.22 

func (r *Rand) Uint64() uint64

Uint64 returns a pseudo-random 64-bit value as a uint64.

-

func (*Rand) Uint64N 1.22 

func (r *Rand) Uint64N(n uint64) uint64

Uint64N returns, as a uint64, a non-negative pseudo-random number in the half-open interval [0,n). It panics if n == 0.

-

func (*Rand) UintN 1.22 

func (r *Rand) UintN(n uint) uint

UintN returns, as a uint, a non-negative pseudo-random number in the half-open interval [0,n). It panics if n == 0.

-

type Source 1.22

A Source is a source of uniformly-distributed pseudo-random uint64 values in the range [0, 1<<64).

-

A Source is not safe for concurrent use by multiple goroutines.

-
type Source interface {
-    Uint64() uint64
-}

type Zipf 1.22

A Zipf generates Zipf distributed variates.

-
type Zipf struct {
-    // contains filtered or unexported fields
-}
-

func NewZipf 1.22 

func NewZipf(r *Rand, s float64, v float64, imax uint64) *Zipf

NewZipf returns a Zipf variate generator. The generator generates values k ∈ [0, imax] such that P(k) is proportional to (v + k) ** (-s). Requirements: s > 1 and v >= 1.

-

func (*Zipf) Uint64 1.22 

func (z *Zipf) Uint64() uint64

Uint64 returns a value drawn from the Zipf distribution described by the Zipf object.

-

- © Google, Inc.
Licensed under the Creative Commons Attribution License 3.0.
- http://golang.org/pkg/math/rand/v2/ -

-
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