RottenFish : Random Poisson Distribution

Licence

RottenFish is under MIT Licence and is written By Emmanuel Cervetti

Abstract

RottenFish is a very fast Poisson Distribution (X,K) approximate implementation for normal and extreme values.

• Number of occurences K up to 2^32 (non inclusive)
• X down to 2^-16 (non inclusive)

The main goal is to provide a very fast random generator that follow a Poisson Distribution usable for real time critical need.

For example, a constant average of only ~0.2 ns per random value is needed on a i5-4258U CPU @ 2.40GHz (2014 dual core laptop)

It's not intended to be monte-carlo critical accurate, but to give a credible magnitude approximation. Totaly suitable for videogames, CGI, ...

The library works using precomputed data tables (~4K of data) . With some bit-like magnitude and linear interpolation, it try to give you the best values matching your experiment variables.

The random generator service underlying is a Xor Shift "Marsaglia", a good implementation when speed targeting.

EXAMPLE USE when static linked

#include <iostream>
#include "Src/RottenFish.h"

RottenFish *rottenFishOperator = RottenFish::getInstance();
/*
 * Load the Poisson variables
 */
int k = 111042 ;
double x = 0.07 ;
rottenFishOperator->loadExperience(x,k);

/*
 * Enjoy yourself !
 */
 
//If I launch 111042 arrows towards a target , on a 7 % area of this target, I could have.....
std::cout << "If I launch " << k << " arrows towards a target , on a "<< 100*x << " % area of this target, I could have..... ";

//7831 arrows. 
std::cout <<  rottenFishOperator->getSimulation() << " arrows." << std::endl;

//Or 7748 arrows.
std::cout << "Or " <<  rottenFishOperator->getSimulation() << " arrows." << std::endl;

//Or 7757 arrows.
std::cout << "Or " <<  rottenFishOperator->getSimulation() << " arrows." << std::endl;

//Or 7790 arrows.
std::cout << "Or " <<  rottenFishOperator->getSimulation() << " arrows." << std::endl;

//Or 7708 arrows.
std::cout << "Or " <<  rottenFishOperator->getSimulation() << " arrows." << std::endl;

//Or 7864 arrows.
std::cout << "Or " <<  rottenFishOperator->getSimulation() << " arrows." << std::endl;

//Or 7693 arrows.
std::cout << "Or " <<  rottenFishOperator->getSimulation() << " arrows." << std::endl;