std::lognormal_distribution - cppreference.com (original) (raw)

std::lognormal_distribution

| | | | | -------------------------------------------------------------------- | | ------------- | | template< class RealType = double > class lognormal_distribution; | | (since C++11) |

The lognormal_distribution random number distribution produces random numbers x > 0 according to a Log-normal distribution:

\({\small f(x;m,s) = \frac{1}{sx\sqrt{2\pi} } \exp{(-\frac{ {(\ln{x} - m)}^{2} }{2{s}^{2} })} }\)f(x; m,s) = exp⎛
⎜
⎝- ⎞
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⎠

The parameters m and s are, respectively, the mean and standard deviation of the natural logarithm of x.

std::lognormal_distribution satisfies all requirements of RandomNumberDistribution.

Contents

[edit] Template parameters

RealType - The result type generated by the generator. The effect is undefined if this is not one of float, double, or long double.

[edit] Member types

Member type Definition
result_type (C++11) RealType
param_type (C++11) the type of the parameter set, see RandomNumberDistribution.

[edit] Member functions

(constructor)(C++11) constructs new distribution (public member function) [edit]
reset(C++11) resets the internal state of the distribution (public member function) [edit]
Generation
operator()(C++11) generates the next random number in the distribution (public member function) [edit]
Characteristics
ms(C++11) returns the distribution parameters (public member function) [edit]
param(C++11) gets or sets the distribution parameter object (public member function) [edit]
min(C++11) returns the minimum potentially generated value (public member function) [edit]
max(C++11) returns the maximum potentially generated value (public member function) [edit]

[edit] Non-member functions

[edit] Example

Possible output:

2 3 *** 4 ************* 5 *************** 6 ********* 7 **** 8 * 9 a b c