lstg::Random Class Reference

Public Member Functions
function	below (local n)
function	beta (local alpha, local beta)
function	choice (local array)
	lstg.Random More...
function	create (local seed)
function	expo (local lambda)
function	Float (local a, local b)
function	gamma (local alpha, local beta)
function	gauss (local mu, local sigma)
function	getSeed ()
function	Int (local a, local b)
	lstg.Random More...
function	log_normal (local mu, local sigma)
function	normal (local mu, local sigma)
function	pareto (local alpha)
function	randFloat (local a, local b)
function	randInt (local a, local b)
function	randSign ()
function	range (local start, local stop, local step)
	Choose a random item from range(start, stop[, step]). More...
function	sample (local array, local k)
function	sample_range (local start, local stop, local step, local k)
function	sample_weighted (local array, local weight, local k)
function	Seed (local n)
function	setSeed (local seed)
function	shuffle (local array)
function	Sign ()
function	triangular (local low, local high, local mode)
function	uniform (local a, local b)
function	vonMises (local mu, local kappa)
function	weibull (local alpha, local beta)

Member Function Documentation

below()

function below

(

local

n

)

Return a random int in the range [0, n).

Return 0 if n is 0.

Parameters

n

number

Returns

number

beta()

function beta	(	local	alpha,
		local	beta
	)

Beta distribution.

Conditions on the parameters are alpha > 0 and beta > 0.

Returned values range between 0 and 1.

Parameters

alpha	number
beta	number

Returns

number

choice()

function choice

(

local

array

)

lstg.Random

Choose a random element from a non-empty array.

Parameters

array

table

create()

function create

(

local

seed

)

Parameters

seed

number

Returns

lstg.Random

重载

fun(self:lstg.Random):lstg.Random

expo()

function expo

(

local

lambda

)

Exponential distribution.

lambda is 1.0 divided by the desired mean. It should be

nonzero. Returned values range from 0 to

positive infinity if lambda is positive, and from negative

infinity to 0 if lambda is negative.

Parameters

lambda

number

Returns

number

Float()

function Float	(	local	a,
		local	b
	)

生成[a,b]范围的随机浮点数

Parameters

a	number
b	number

Returns

number

gamma()

function gamma	(	local	alpha,
		local	beta
	)

Gamma distribution. (Not the gamma function)

Conditions on the parameters are alpha > 0 and beta > 0.

Parameters

alpha	number
beta	number

Returns

number

gauss()

function gauss	(	local	mu,
		local	sigma
	)

Gaussian distribution.

mu is the mean, and sigma is the standard deviation. This is

slightly faster than the normal() function.

Parameters

mu	number
sigma	number

Returns

number

getSeed()

function getSeed

(

)

Returns

number

Int()

function Int	(	local	a,
		local	b
	)

lstg.Random

生成[a,b]范围的随机整数

Parameters

a	number
b	number

Returns

number

log_normal()

function log_normal	(	local	mu,
		local	sigma
	)

Log normal distribution.

If you take the natural logarithm of this distribution, you'll get a

normal distribution with mean mu and standard deviation sigma.

mu can have any value, and sigma must be greater than zero.

Parameters

mu	number
sigma	number

Returns

number

normal()

function normal	(	local	mu,
		local	sigma
	)

Normal distribution.

mu is the mean, and sigma is the standard deviation.

Parameters

mu	number
sigma	number

Returns

number

pareto()

function pareto

(

local

alpha

)

Pareto distribution.

alpha is the shape parameter.

Parameters

alpha

number

Returns

number

randFloat()

function randFloat	(	local	a,
		local	b
	)

get random float in range [a, b]

Parameters

a	number
b	number

Returns

number

randInt()

function randInt	(	local	a,
		local	b
	)

get random int32 in range [a, b]

Parameters

a	number
b	number

Returns

number

randSign()

function randSign

(

)

get random 1 or -1

Returns

number

range()

function range	(	local	start,
		local	stop,
		local	step
	)

Choose a random item from range(start, stop[, step]).

Parameters

start	number
stop	number
step	number

Returns

number

重载

fun(self:lstg.Random, start:number):number

sample()

function sample	(	local	array,
		local	k
	)

Chooses k unique random elements from an array.

Returns a new array.

Parameters

array	table
k	number

Returns

table

sample_range()

function sample_range	(	local	start,
		local	stop,
		local	step,
		local	k
	)

Chooses k unique random numbers from a range.

Returns an array.

Parameters

start	number
stop	number
step	number
k	number

Returns

table

sample_weighted()

function sample_weighted	(	local	array,
		local	weight,
		local	k
	)

Chooses k unique random elements from an array by given weight.

Reference: https://www.sciencedirect.com/science/article/abs/pii/S002001900500298X

Returns an array.

Parameters

array	table
weight	table
k	number

Returns

table

Seed()

function Seed

(

local

n

)

设置随机数种子

Parameters

n

number

setSeed()

function setSeed

(

local

seed

)

Parameters

seed

number

Returns

lstg.Random

shuffle()

function shuffle

(

local

array

)

Shuffle array in place.

Parameters

array

table

Sign()

function Sign

(

)

随机生成1或-1

Returns

number

triangular()

function triangular	(	local	low,
		local	high,
		local	mode
	)

Parameters

low	number
high	number
mode	number

Returns

number

重载

fun(self:lstg.Random, low:number, high:number):number

重载

fun(self:lstg.Random):number

uniform()

function uniform	(	local	a,
		local	b
	)

Uniform distribution.

Get a random number in the range [a, b].

Parameters

a	number
b	number

Returns

number

vonMises()

function vonMises	(	local	mu,
		local	kappa
	)

von Mises distribution (Circular data distribution).

mu is the mean angle, expressed in radians between 0 and 2*pi, and

kappa is the concentration parameter, which must be greater than or

equal to zero. If kappa is equal to zero, this distribution reduces

to a uniform random angle over the range 0 to 2*pi.

Parameters

mu	number
kappa	number

Returns

number

weibull()

function weibull	(	local	alpha,
		local	beta
	)

Weibull distribution.

alpha is the scale parameter and beta is the shape parameter.

Parameters

alpha	number
beta	number

Returns

number

---

The documentation for this class was generated from the following files:

• src/core/math.lua.hpp
• src/core_x/ext/Random.lua.hpp