Defined in header <random> | ||
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template< class RealType = double > class gamma_distribution; | (since C++11) |
Produces random positive floating-point values x, distributed according to probability density function: P(x|α,β) =
| e-x/β |
| βα · Γ(α) |
where α is known as the shape parameter and β is known as the scale parameter. The shape parameter is sometimes denoted by the letter k and the scale parameter is sometimes denoted by the letter θ.
For floating-point α, the value obtained is the sum of α independent exponentially distributed random variables, each of which has a mean of β
std::gamma_distribution satisfies RandomNumberDistribution.
| RealType | - | The result type generated by the generator. The effect is undefined if this is not one of float, double, or long double. |
| Member type | Definition |
|---|---|
result_type | RealType |
param_type | the type of the parameter set, see RandomNumberDistribution. |
| constructs new distribution (public member function) |
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| resets the internal state of the distribution (public member function) |
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Generation |
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| generates the next random number in the distribution (public member function) |
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Characteristics |
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| returns the distribution parameters (public member function) |
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| gets or sets the distribution parameter object (public member function) |
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| returns the minimum potentially generated value (public member function) |
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| returns the maximum potentially generated value (public member function) |
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| compares two distribution objects (function) |
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| performs stream input and output on pseudo-random number distribution (function template) |
Weisstein, Eric W. "Gamma Distribution." From MathWorld--A Wolfram Web Resource.
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