freebsd-dev/gnu/lib/libg++/include/Normal.h

// 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 free
software; you can redistribute it and/or modify it under the terms of
the GNU Library General Public License as published by the Free
Software Foundation; either version 2 of the License, or (at your
option) any later version.  This library is distributed in the hope
that it will be useful, but WITHOUT ANY WARRANTY; without even the
implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
PURPOSE.  See the GNU Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with this library; if not, write to the Free Software
Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#ifndef _Normal_h
#ifdef __GNUG__
#pragma interface
#endif
#define _Normal_h

#include <Random.h>

class Normal: public Random {
    char haveCachedNormal;
    double cachedNormal;

protected:
    double pMean;
    double pVariance;
    double pStdDev;

public:
    Normal(double xmean, double xvariance, RNG *gen);
    double mean();
    double mean(double x);
    double variance();
    double variance(double x);
    virtual double operator()();
};


inline Normal::Normal(double xmean, double xvariance, RNG *gen)
: Random(gen) {
  pMean = xmean;
  pVariance = xvariance;
  pStdDev = sqrt(pVariance);
  haveCachedNormal = 0;
}

inline double Normal::mean() { return pMean; };
inline double Normal::mean(double x) {
  double t=pMean; pMean = x;
  return t;
}

inline double Normal::variance() { return pVariance; }
inline double Normal::variance(double x) {
  double t=pVariance; pVariance = x;
  pStdDev = sqrt(pVariance);
  return t;
};

#endif