AnalysisSystemForRadionucli.../include/armadillo_bits/arma_rng_cxx11.hpp
2024-06-04 15:25:02 +08:00

144 lines
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// Copyright (C) 2013-2015 National ICT Australia (NICTA)
//
// This Source Code Form is subject to the terms of the Mozilla Public
// License, v. 2.0. If a copy of the MPL was not distributed with this
// file, You can obtain one at http://mozilla.org/MPL/2.0/.
// -------------------------------------------------------------------
//
// Written by Conrad Sanderson - http://conradsanderson.id.au
//! \addtogroup arma_rng_cxx11
//! @{
#if defined(ARMA_USE_CXX11)
class arma_rng_cxx11
{
public:
typedef std::mt19937_64::result_type seed_type;
inline void set_seed(const seed_type val);
arma_inline int randi_val();
arma_inline double randu_val();
arma_inline double randn_val();
template<typename eT>
arma_inline void randn_dual_val(eT& out1, eT& out2);
template<typename eT>
inline void randi_fill(eT* mem, const uword N, const int a, const int b);
inline static int randi_max_val();
template<typename eT>
inline void randg_fill(eT* mem, const uword N, const double a, const double b);
private:
arma_aligned std::mt19937_64 engine; // typedef for std::mersenne_twister_engine with preset parameters
arma_aligned std::uniform_int_distribution<int> i_distr; // by default uses a=0, b=std::numeric_limits<int>::max()
arma_aligned std::uniform_real_distribution<double> u_distr; // by default uses [0,1) interval
arma_aligned std::normal_distribution<double> n_distr; // by default uses mean=0.0 and stddev=1.0
};
inline
void
arma_rng_cxx11::set_seed(const arma_rng_cxx11::seed_type val)
{
engine.seed(val);
}
arma_inline
int
arma_rng_cxx11::randi_val()
{
return i_distr(engine);
}
arma_inline
double
arma_rng_cxx11::randu_val()
{
return u_distr(engine);
}
arma_inline
double
arma_rng_cxx11::randn_val()
{
return n_distr(engine);
}
template<typename eT>
arma_inline
void
arma_rng_cxx11::randn_dual_val(eT& out1, eT& out2)
{
out1 = eT( n_distr(engine) );
out2 = eT( n_distr(engine) );
}
template<typename eT>
inline
void
arma_rng_cxx11::randi_fill(eT* mem, const uword N, const int a, const int b)
{
std::uniform_int_distribution<int> local_i_distr(a, b);
for(uword i=0; i<N; ++i)
{
mem[i] = eT(local_i_distr(engine));
}
}
inline
int
arma_rng_cxx11::randi_max_val()
{
return std::numeric_limits<int>::max();
}
template<typename eT>
inline
void
arma_rng_cxx11::randg_fill(eT* mem, const uword N, const double a, const double b)
{
std::gamma_distribution<double> g_distr(a,b);
for(uword i=0; i<N; ++i)
{
mem[i] = eT(g_distr(engine));
}
}
#endif
//! @}