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Diffstat (limited to 'gnu/lib/libg++/include/HypGeom.h')
-rw-r--r-- | gnu/lib/libg++/include/HypGeom.h | 70 |
1 files changed, 70 insertions, 0 deletions
diff --git a/gnu/lib/libg++/include/HypGeom.h b/gnu/lib/libg++/include/HypGeom.h new file mode 100644 index 0000000..e16e655 --- /dev/null +++ b/gnu/lib/libg++/include/HypGeom.h @@ -0,0 +1,70 @@ +// 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 _HyperGeometric_h +#ifdef __GNUG__ +#pragma interface +#endif +#define _HyperGeometric_h + +#include <Random.h> + +class HyperGeometric: public Random { +protected: + double pMean; + double pVariance; + double pP; + void setState(); + +public: + HyperGeometric(double mean, double variance, RNG *gen); + + double mean(); + double mean(double x); + double variance(); + double variance(double x); + + virtual double operator()(); +}; + + +inline void HyperGeometric::setState() { + double z = pVariance / (pMean * pMean); + pP = 0.5 * (1.0 - sqrt((z - 1.0) / ( z + 1.0 ))); +} + +inline HyperGeometric::HyperGeometric(double mean, double variance, RNG *gen) +: Random(gen) { + pMean = mean; pVariance = variance; + setState(); +} + +inline double HyperGeometric::mean() { return pMean; }; + +inline double HyperGeometric::mean(double x) { + double t = pMean; pMean = x; + setState(); return t; +} + +inline double HyperGeometric::variance() { return pVariance; } + +inline double HyperGeometric::variance(double x) { + double t = pVariance; pVariance = x; + setState(); return t; +} + +#endif |