InterfaceUnit - Random

The EbsScript unit @Random contains functions for generating various random distributions, among others

 

Name	Purpose	Arguments	Return value	Example
rndUniformIntegerDistribution	Function generates a uniformly distributed integer random number in the range [minimum, maximum]	1: INTEGER: minimum 2: INTEGER: maximum	INTEGER:
rndUniformRealDistribution	Function generates a uniformly distributed real random number in the range [minimum, maximum]	1: REAL: minimum 2: REAL: maximum	REAL:
rndNormalDistribution	Function generates a normally distributed real random number with the mean value mean and standard deviation stddef	1: REAL: mean 2: REAL: stddev	REAL:

The functions are based on the corresponding C++ classes (see http://en.cppreference.com/w/cpp/numeric/random ) and they all use a 64-bit Mersenne Twister algorithm (mt19937_64 by Matsumoto and Nishimura, 2000) as generator.

The complete list comprises:

Uniform distributions:
function rndUniformIntegerDistribution(minimum:integer = 0; maximum:integer = 2147483647):integer; internal;
function rndUniformRealDistribution(minimum:real = 0; maximum:real = 1):real; internal;

Bernoulli distributions:
function rndBernoulliDistribution(p_true:real = 0.5):Boolean; internal;
function rndBinomialDistribution(trials:integer = 1; p_true:real = 0.5):integer; internal;
function rndnegativeBinomialDistribution(fail_trials:integer = 1; p_true:real = 0.5):integer; internal;
function rndGeometricDistribution(p_true:real = 0.5):integer; internal;

Poisson distributions:
function rndPoissonDistribution(mean:real = 1.0):integer; internal;
function rndExponentialDistribution(lambda:real = 1.0):real; internal;
function rndGammaDistribution(alpha:real = 1.0; beta:real = 1.0):real; internal;
function rndWeibullDistribution(a:real = 1.0; b:real = 1.0):real; internal;
function rndExtremeValueDistribution(a:real = 0.0; b:real = 1.0):real; internal;

Normal distributions:
function rndNormalDistribution(mean:real = 0.0; stddev:real = 1.0):real; internal;
function rndLognormalDistribution(m:real = 0.0; shape:real = 1.0):real; internal;
function rndChiSquaredDistribution(n:real = 1.0):real; internal;
function rndCauchyDistribution(a:real = 0.0; b:real = 1.0):real; internal;
function rndFisherFDistribution(m:real = 1.0; n:real = 1.0):real; internal;
function rndStudentTDistribution(n:real = 1.0):real; internal;