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#ifndef BaseNumericalRandomGenerator_H
#define BaseNumericalRandomGenerator_H
/**
* This abstract class provides a C++ version of the REMT package from
* Ronald Kleiss.
*
* In the constructor, the probability density function according to
* which random numbers have to be generated is numerically integrated
* and inversed. The arguments are the generation bounds, the size of
* the internal numerical tables, and the number of iterations for
* integration and inversion.
*
* The method generate() generates random number according to the
* aforementioned probability density function(). The latter must be
* implemented in a real class inheriting from BaseNumericalRandomGenerator.
* (This fuction cannot be abstract, because the constructor uses it.)
* A normal flat random generation between 0 and 1 is performed otherwise.
*
* \author Patrick Janot
* $Date: 12 Jan 2004 14:40 */
#include <vector>
class RandomEngineAndDistribution;
class BaseNumericalRandomGenerator {
public:
/// Constructor that perform the necessary integration and inversion steps
/// xmin and xmax are the generation bounds, n is the internal table size
/// and iter is the number of iterations for the numerical part.
BaseNumericalRandomGenerator(double xmin = 0., double xmax = 1., int n = 1000, int iter = 6);
/// Default destructor
virtual ~BaseNumericalRandomGenerator() {}
/// The initialization (numerical integarion, inversion)
void initialize();
/// The random generation according to function()
double generate(RandomEngineAndDistribution const*) const;
/// The random generation according to function(), refined to generate
/// as an exponential in each of the intervals
double generateExp(RandomEngineAndDistribution const*) const;
/// The random generation according to function(), refined to generate
/// as a linear function in each of the intervals
double generateLin(RandomEngineAndDistribution const*) const;
// The probability density function, to be implemented in the real class
virtual double function(double x) = 0;
/// To shoot in a given interval
bool setSubInterval(double x1, double x2);
protected:
std::vector<double> sampling;
std::vector<double> f;
double xmin, xmax;
int n, iter;
double rmin, deltar;
private:
int m;
};
#endif
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