/*
 *
 * Copyright (c) 1994
 * Hewlett-Packard Company
 *
 */

#ifndef STATIST_H

#define STATIST_H

extern "C" {
double drand48 ( );
}

double H(int n);

class zipf
{
private:
    double ln_n;
    double c; //inverse of H(n) 
public:
    zipf(int size);
    void reset(int size);
    double p(int i);
    int random();
};

class exponential
{
private:
    double mu;
public:
    exponential(double x);
    void reset(double x);
    double random();
};

class skewed_boolean
{
private:
    double r;
public:
    skewed_boolean(double skew);
    void reset(double skew);
    int random();
};

class permutation
{
private:
    int n;
    int* Map;
    int* Inverse;
    void swap(int i, int j)
    {
	int t = Map[i];
	Inverse[Map[i]] = j;
	Inverse[Map[j]] = i;
	Map[i] = Map[j];
	Map[j] = t;
    }
public:
    permutation(int size);
    ~permutation();
    void randomize();
    int map(int i)
    {
	return Map[i];
    }
    int inverse(int i)
    {
	return Inverse[i];
    }
};
    
#endif