Functions related to the generation of random numbers. More...

Functions
double	rng::powerlaw_rand (std::vector< double > &param, std::mt19937 &_engine)
	Generates a random real number following a power-law distribution of the form $\rho(x) \propto x^{-\gamma}$ with $x\in(x_\mathrm{min},\infty)$ . More...

double	rng::powerlaw_m1 (std::vector< double > &param)
	Returns the first moment of a power-law distribution of the form $\rho(x) \propto x^{-\gamma}$ with $x\in(x_\mathrm{min},\infty)$ . More...

double	rng::powerlaw_hardcutoff_rand (std::vector< double > &param, std::mt19937 &_engine)
	Generates a random real number following a power-law distribution of the form $\rho(x)\propto x^{-\gamma}$ with $x\in(x_\mathrm{min},x_\mathrm{max})$ (i.e., hard cut-off). More...

double	rng::powerlaw_hardcutoff_m1 (std::vector< double > &param)
	Returns the first moment of a power-law distribution of the form $\rho(x) \propto x^{-\gamma}$ with $x\in(x_\mathrm{min},x_\mathrm{max})$ (i.e., hard cut-off). More...

double	rng::exponential_rand (std::vector< double > &param, std::mt19937 &_engine)
	Generates a random real number following an exponential distribution of the form $\rho(x)\propto \mathrm{e}^{-x/\beta}$ with $x\in(0,\infty)$ . More...

double	rng::exponential_m1 (double param)
	Returns the first moment of an exponential distribution of the form $\rho(x)\propto \mathrm{e}^{-x/\beta}$ with $x\in(0,\infty)$ . More...

double	rng::gamma_rand (std::vector< double > &param, std::mt19937 &_engine)
	Generates a random real number following a gamma distribution of the form $\rho(x)\propto x^{\alpha-1}\mathrm{e}^{-x/\beta}$ with $x\in(0,\infty)$ . More...

double	rng::gamma_m1 (std::vector< double > param)
	Returns the first moment of a gamma distribution of the form $\rho(x)\propto x^{\alpha-1}\mathrm{e}^{-x/\beta}$ with $x\in(0,\infty)$ . More...

Detailed Description

Functions related to the generation of random numbers.

Set of functions that generate random numbers from a variety of distributions and provides some of their moments and cumulants. Notice that all the functions listed in this group are within the "rng" namespace.

Function Documentation

double rng::exponential_m1 ( double param )

Returns the first moment of an exponential distribution of the form $\rho(x)\propto \mathrm{e}^{-x/\beta}$ with $x\in(0,\infty)$ .

Parameters

param[0] Scale parameter ( $\beta$ ).

Returns: Average of an exponential distribution defined by scale parameter $\beta$ .

double rng::exponential_rand	(	std::vector< double > &	param,
		std::mt19937 &	_engine
	)

Generates a random real number following an exponential distribution of the form $\rho(x)\propto \mathrm{e}^{-x/\beta}$ with $x\in(0,\infty)$ .

Parameters

param[0] Scale parameter ( $\beta$ ).

Returns: Real number between 0 and $\infty$ distributed as an exponential distribution with scale parameter $\beta$ .

double rng::gamma_m1 ( std::vector< double > param )

Returns the first moment of a gamma distribution of the form $\rho(x)\propto x^{\alpha-1}\mathrm{e}^{-x/\beta}$ with $x\in(0,\infty)$ .

Parameters

param[0]	Shape parameter ( $\alpha$ ).
param[1]	Scale parameter ( $\beta$ ).

Returns: Average of a gamma distribution defined by shape parameter $\alpha$ and scale parameter $\beta$ .

double rng::gamma_rand	(	std::vector< double > &	param,
		std::mt19937 &	_engine
	)

Generates a random real number following a gamma distribution of the form $\rho(x)\propto x^{\alpha-1}\mathrm{e}^{-x/\beta}$ with $x\in(0,\infty)$ .

Parameters

param[0]	Shape parameter ( $\alpha$ ).
param[1]	Scale parameter ( $\beta$ ).

Returns: Real number between 0 and $\infty$ distributed as a gamma distribution with a shape parameter $\alpha$ and a scale parameter $\beta$ .

double rng::powerlaw_hardcutoff_m1 ( std::vector< double > & param )

Returns the first moment of a power-law distribution of the form $\rho(x) \propto x^{-\gamma}$ with $x\in(x_\mathrm{min},x_\mathrm{max})$ (i.e., hard cut-off).

Parameters

param[0]	Exponent of the distribution ( $\gamma$ ).
param[1]	Lower bound of the distribution ( $x_\mathrm{min}$ ).
param[2]	Upper bound of the distribution ( $x_\mathrm{max}$ ).

Returns: Average of a power-law distribution defined by exponent $\gamma$ , a lower bound $x_\mathrm{min}$ and a upper bound $x_\mathrm{max}$ .

double rng::powerlaw_hardcutoff_rand	(	std::vector< double > &	param,
		std::mt19937 &	_engine
	)

Generates a random real number following a power-law distribution of the form $\rho(x)\propto x^{-\gamma}$ with $x\in(x_\mathrm{min},x_\mathrm{max})$ (i.e., hard cut-off).

Parameters

param[0]	Exponent of the distribution ( $\gamma$ ).
param[1]	Lower bound of the distribution ( $x_\mathrm{min}$ ).
param[2]	Upper bound of the distribution ( $x_\mathrm{max}$ ).

Returns: Real number between $x_\mathrm{min}$ and $x_\mathrm{max}$ distributed as a power-law distribution with exponent $\gamma$ .

double rng::powerlaw_m1 ( std::vector< double > & param )

Returns the first moment of a power-law distribution of the form $\rho(x) \propto x^{-\gamma}$ with $x\in(x_\mathrm{min},\infty)$ .

Parameters

param[0]	Exponent of the distribution ( $\gamma$ ).
param[1]	Lower bound of the distribution ( $x_\mathrm{min}$ ).

Returns: Average of a power-law distribution defined by exponent $\gamma$ and lower bound $x_\mathrm{min}$ . Returns infinite if the average diverges, and print a warning message on screen.

double rng::powerlaw_rand	(	std::vector< double > &	param,
		std::mt19937 &	_engine
	)

Generates a random real number following a power-law distribution of the form $\rho(x) \propto x^{-\gamma}$ with $x\in(x_\mathrm{min},\infty)$ .

Parameters

param[0]	Exponent of the distribution ( $\gamma$ ).
param[1]	Lower bound of the distribution ( $x_\mathrm{min}$ ).

Returns: Real number between $x_\mathrm{min}$ and $\infty$ distributed as a power-law distribution with exponent $\gamma$ .