std::exponential_distribution
Da cppreference.com
 |
This page has been machine-translated from the English version of the wiki using Google Translate.
The translation may contain errors and awkward wording. Hover over text to see the original version. You can help to fix errors and improve the translation. For instructions click here. |
| Definido no cabeçalho <random>
|
||
| template< class RealType = double > class exponential_distribution; |
(desde C++11) | |
Produz aleatórias não-negativas valores de ponto flutuante x, distribuídos de acordo com a função densidade de probabilidade:
Original:
Produces random non-negative floating-point values x, distributed according to probability density function:
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
You can help to correct and verify the translation. Click here for instructions.
- P(x|λ) = λe-λx
O valor obtido é o tempo / distância até que o próximo evento aleatório se acontecimentos aleatórios ocorrem a uma taxa constante λ por unidade de tempo / distância. Por exemplo, esta distribuição descreve o tempo entre os cliques de um contador Geiger ou a distância entre os pontos de mutação numa cadeia de DNA.
Original:
The value obtained is the time/distance until the next random event if random events occur at constant rate λ per unit of time/distance. For example, this distribution describes the time between the clicks of a Geiger counter or the distance between point mutations in a DNA strand.
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
You can help to correct and verify the translation. Click here for instructions.
Isto é o equivalente de std::geometric_distribution contínua
Original:
This is the continuous counterpart of std::geometric_distribution
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
You can help to correct and verify the translation. Click here for instructions.
[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
|
RealType |
param_type
|
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. | |
| retorna o lambda parâmetro de distribuição (taxa de eventos) Original: returns the lambda distribution parameter (rate of events) 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) | |
| 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 particles decay once per second on average, // how much time, in seconds, until the next one? std::exponential_distribution<> d(1); std::map<int, int> hist; for(int n=0; n<10000; ++n) { ++hist[2*d(gen)]; } for(auto p : hist) { std::cout << std::fixed << std::setprecision(1) << p.first/2.0 << '-' << (p.first+1)/2.0 << ' ' << std::string(p.second/200, '*') << '\n'; }
Saída:
0.0-0.5 ******************* 0.5-1.0 *********** 1.0-1.5 ******* 1.5-2.0 **** 2.0-2.5 ** 2.5-3.0 * 3.0-3.5 3.5-4.0
[editar] Links externos
Weisstein, Eric W. "Exponential Distribution." De MathWorld - Um recurso Web Wolfram.
Original:
Weisstein, Eric W. "Exponential 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.
You can help to correct and verify the translation. Click here for instructions.
