com.qbpsimulator.engine.utils

Class RandomGenerator

java.lang.Object

com.qbpsimulator.engine.utils.RandomGenerator

public class RandomGenerator
extends Object

Random number generator. Supports uniform, normal and exponential distributions for random numbers.

Author:

Madis Abel

Constructor Summary

Constructors

Constructor and Description
RandomGenerator() Initializes random generators.

Method Summary

Modifier and Type	Method and Description
double	exponential(double lambda) Random number with exponential distribution
double	fromDistributionInfo(DistributionInfo di) Returns random number from DistributionInfo instance
double	gamma(Double mean, Double variance) Random number from gamma distribution
int	getSeed() Gets the seed of random generator
double	lognormal(Double mean, Double variance) Random number from lognormal distribution
double	normal(double mean, double stdDev) Random number with truncated normal distribution.
double	random() Random number with uniform distribution.
void	setSeed(int seed) Sets the seed of random generator
double	triangular(Double mode, Double minA, Double maxB) Random number from triangular distribution
double	uniform(double min, double max) Random number from uniform distribution

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

RandomGenerator

public RandomGenerator()

Initializes random generators.

Method Detail

getSeed

public int getSeed()

Gets the seed of random generator

Returns:

seed

setSeed

public void setSeed(int seed)

Sets the seed of random generator

Parameters:

seed - seed

normal

public double normal(double mean,
                     double stdDev)

Random number with truncated normal distribution. Will not return negative number.

Parameters:

mean - mean

stdDev - standard deviation

Returns:

random number

exponential

public double exponential(double lambda)

Random number with exponential distribution

Parameters:

lambda - lambda parameter, 1/mean

Returns:

random number

uniform

public double uniform(double min,
                      double max)

Random number from uniform distribution

Parameters:

min - minimum value

max - maximum value

Returns:

random number from range [min, max]

lognormal

public double lognormal(Double mean,
                        Double variance)

Random number from lognormal distribution

Parameters:

mean -

variance -

Returns:

triangular

public double triangular(Double mode,
                         Double minA,
                         Double maxB)

Random number from triangular distribution

Parameters:

mode, - a < b, a <= mode <= b

minA - minimum at a, a < b, a <= mode <= b

maxB - maximum at b, a < b, a <= mode <= b

Returns:

gamma

public double gamma(Double mean,
                    Double variance)

Random number from gamma distribution

Parameters:

mean -

variance -

Returns:

fromDistributionInfo

public double fromDistributionInfo(DistributionInfo di)
                            throws ProcessValidationException

Returns random number from DistributionInfo instance

Parameters:

di - distribution information

Returns:

random number

Throws:

ProcessValidationException

random

public double random()

Random number with uniform distribution. Equal to Math.random(), from range [0, 1)

Returns:

random