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std::normal_distribution - cppreference.com

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template< class RealType = double > class normal_distribution;

 (desde C++11)

Normal (ou guassian) a distribuição de números aleatórios:

f(x; μ,σ) = None exp⎛
⎜
⎝- ⎛
⎜
⎝⎞
⎟
⎠2
⎞
⎟
⎠

Com a dizer μ eo desvio padrão (' stddev) σ.

Original:

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Tipos de membro

Tipo de membro

Original:

Member type

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 Definition
result_type RealType
param_type

o tipo do conjunto de parâmetros, não especificado

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the type of the parameter set, unspecified

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Funções de membro

constrói nova distribuição

Original:

constructs new distribution

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(função pública membro) [edit]

redefine o estado interno da distribuição

Original:

resets the internal state of the distribution

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Geração

Original:

Generation

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gera o próximo número aleatório na distribuição

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generates the next random number in the distribution

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Características

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Characteristics

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retorna o parâmetro médio de distribuição (μ)

Original:

returns the mean (μ) distribution parameter

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retorna o desvio padrão do parâmetro de distribuição (σ)

Original:

returns the standard deviation (σ) distribution parameter

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(função pública membro) [edit]

obtém ou define o objeto de parâmetro de distribuição

Original:

gets or sets the distribution parameter object

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retorna o valor mínimo potencialmente gerado

Original:

returns the minimum potentially generated value

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retorna o valor máximo potencialmente gerado

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returns the maximum potentially generated value

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Não-membros funções

compara dois objetos de distribuição

Original:

compares two distribution objects

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(função) [edit]

executa fluxo de entrada e saída em pseudo-aleatório distribuição de números

Original:

performs stream input and output on pseudo-random number distribution

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(função) [edit]

Exemplo

#include <iostream>
#include <iomanip>
#include <string>
#include <map>
#include <random>
#include <cmath>
int main()
{
    std::random_device rd;
    std::mt19937 gen(rd());

    // values near the mean are the most likely
    // standard deviation affects the dispersion of generated values from the mean
    std::normal_distribution<> d(5,2);

    std::map<int, int> hist;
    for(int n=0; n<10000; ++n) {
        ++hist[std::round(d(gen))];
    }
    for(auto p : hist) {
        std::cout << std::fixed << std::setprecision(1) << std::setw(2)
                  << p.first << ' ' << std::string(p.second/200, '*') << '\n';
    }
}

Saída: 

-2 
-1 
 0 
 1 *
 2 ***
 3 ******
 4 ********
 5 **********
 6 ********
 7 *****
 8 ***
 9 *
10 
11 
12

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