std::poisson_distribution
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| Definido no cabeçalho <random>
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| template< class IntType = int > class poisson_distribution; |
(desde C++11) | |
Produz aleatória não negativa i valores inteiros, distribuídos de acordo com a função de probabilidade discreta:
Original:
Produces random non-negative integer values i, distributed according to discrete probability function:
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- P(i|μ) =
e-μ
·μii!
The value obtained is the probability of exactly i occurrences of a random event if the expected, mean number of its occurrence under the same conditions (on the same time/space interval) is μ.
[editar] Tipos de membro
| Tipo de membro
Original: Member type The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. |
Definition |
result_type
|
IntType |
param_type
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o tipo do conjunto de parâmetros, não especificado
Original: the type of the parameter set, unspecified The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. |
[editar] Funções de membro
| constrói nova distribuição Original: constructs new distribution The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (função pública membro) | |
| redefine o estado interno da distribuição Original: resets the internal state of the distribution The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (função pública membro) | |
Original: Generation The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. | |
| gera o próximo número aleatório na distribuição Original: generates the next random number in the distribution The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (função pública membro) | |
Original: Characteristics The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. | |
| returns the mean distribution parameter (mean number of occurrences of the event) (função pública membro) | |
| obtém ou define o objeto de parâmetro de distribuição Original: gets or sets the distribution parameter object The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (função pública membro) | |
| retorna o valor mínimo potencialmente gerado Original: returns the minimum potentially generated value The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (função pública membro) | |
| retorna o valor máximo potencialmente gerado Original: returns the maximum potentially generated value The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (função pública membro) | |
[editar] Não-membros funções
| compara dois objetos de distribuição Original: compares two distribution objects The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (função) | |
| executa fluxo de entrada e saída em pseudo-aleatório distribuição de números Original: performs stream input and output on pseudo-random number distribution The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (função) | |
[editar] Exemplo
#include <iostream> #include <iomanip> #include <string> #include <map> #include <random> int main() { std::random_device rd; std::mt19937 gen(rd()); // if an event occurs 4 times a minute on average // how often is it that it occurs n times in one minute? std::poisson_distribution<> d(4); std::map<int, int> hist; for(int n=0; n<10000; ++n) { ++hist[d(gen)]; } for(auto p : hist) { std::cout << p.first << ' ' << std::string(p.second/100, '*') << '\n'; } }
Saída:
0 * 1 ******* 2 ************** 3 ******************* 4 ******************* 5 *************** 6 ********** 7 ***** 8 ** 9 * 10 11 12 13
[editar] Links externos
Weisstein, Eric W. "Poisson Distribution." De MathWorld - Um recurso Web Wolfram.
Original:
Weisstein, Eric W. "Poisson Distribution." From MathWorld--A Wolfram Web Resource.
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
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