Random numbers

Class: Random_number_generator

This is a polymorphic base class for any of the continuous generators described below. Data for an object of this class is 
   name_of_subclass	(listed below for each continuous class)
   data_for_class	(if necessary)

Class: Ransub

Generates random numbers with uniform probability over the range [0,1), using Knuth's subtractive algorithm. Type name: unit_uniform. Data: none.

Class: Ranuniform

Generates random numbers with a uniform distribution. Type name: uniform Data format: 
   double vmin, vmax; // limits of range

Class: Ranlorentz

Generates random numbers with a Lorentzian distribution. Type name: lorentzian Data format: 
   double r; // width of distribution
   double xc; // centre of distribution

Class: Rangauss

Generates random numbers with a Gaussian distribution of unit width, centred on the origin. Type name: unit_gaussian. (No parameters.)

Class: Rangaussgen

Generates random numbers with a Gaussian distribution. Type name: gaussian. Data format: 
   double r; // width of distribution
   double xc; // centre of distribution

Class: Ranexp

Generates random numbers with an exponential distribution. Type name: exponential. Data format: 
   double r; // width of distribution
   double xc; // centre of distribution

Class: Randisexp

Generates random numbers with an exponential distribution of unit width, in the positive arm of the distribution. Type name: unit_positive_exponential. (No parameters.)

Class: Ranset

Generates discrete random outcomes (integers) with a distribution defined by a set of probabilities. Data format: 
number_of_possible_outcomes
For each:
   probability
The probabilities should add up to 1 or less. The index of the outcomes runs from 0 to N-1. If the total probability adds up to less than 1, then the result `none of the above' is given as -1.