// This may look like C code, but it is really -*- C++ -*-/* Copyright (C) 1988 Free Software Foundation    written by Dirk Grunwald (grunwald@cs.uiuc.edu)This file is part of the GNU C++ Library.  This library is freesoftware; you can redistribute it and/or modify it under the terms ofthe GNU Library General Public License as published by the FreeSoftware Foundation; either version 2 of the License, or (at youroption) any later version.  This library is distributed in the hopethat it will be useful, but WITHOUT ANY WARRANTY; without even theimplied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULARPURPOSE.  See the GNU Library General Public License for more details.You should have received a copy of the GNU Library General PublicLicense along with this library; if not, write to the Free SoftwareFoundation, 675 Mass Ave, Cambridge, MA 02139, USA.*/#ifndef _Erlang_h#ifdef __GNUG__#pragma interface#endif#define _Erlang_h 1 #include <Random.h>class Erlang: public Random {protected:    double pMean;    double pVariance;    int k;    double a;    void setState();public:    Erlang(double mean, double variance, RNG *gen);    double mean();    double mean(double x);    double variance();    double variance(double x);    virtual double operator()();};inline void Erlang::setState() {  k = int( (pMean * pMean ) / pVariance + 0.5 );  k = (k > 0) ? k : 1;  a = k / pMean;}inline Erlang::Erlang(double mean, double variance, RNG *gen) : Random(gen){  pMean = mean; pVariance = variance;  setState();}inline double Erlang::mean() { return pMean; }inline double Erlang::mean(double x) {  double tmp = pMean; pMean = x; setState(); return tmp;};inline double Erlang::variance() { return pVariance; }inline double Erlang::variance(double x) {  double tmp = pVariance; pVariance = x; setState(); return tmp;}#endif