forked from amazingfate/loongoffice
9c3e819f06
so we can re-use it in other modules Change-Id: I6057b1e955f745019fd48f91a754279df0f2b948 Reviewed-on: https://gerrit.libreoffice.org/9348 Reviewed-by: Thomas Arnhold <thomas@arnhold.org> Tested-by: Thomas Arnhold <thomas@arnhold.org>
55 lines
1.6 KiB
C++
55 lines
1.6 KiB
C++
/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
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/*
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* This file is part of the LibreOffice project.
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*
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* This Source Code Form is subject to the terms of the Mozilla Public
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* License, v. 2.0. If a copy of the MPL was not distributed with this
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* file, You can obtain one at http://mozilla.org/MPL/2.0/.
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*
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* Contributor(s):
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* Copyright (C) 2012 Tino Kluge <tino.kluge@hrz.tu-chemnitz.de>
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*/
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#include <boost/random.hpp>
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#include <comphelper/random.hxx>
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// this is nothing but a simple wrapper around
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// the boost random generators
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namespace comphelper
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{
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namespace rng
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{
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// underlying random number generator
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// boost::mt19937 implements the Mersenne twister algorithm which
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// is fast and has good statistical properties, it produces integers
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// in the range of [0, 2^32-1] internally
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// memory requirement: 625*sizeof(uint32_t)
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// http://en.wikipedia.org/wiki/Mersenne_twister
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#define BOOST_RNG_ALGO boost::mt19937
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BOOST_RNG_ALGO global_rng;
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// initialises the state of the global random number generator
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// should only be called once at the start of the main programme
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// (note, a few boost::variate_generator<> (like normal) have their
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// own state which would need a reset as well to guarantee identical
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// sequence of numbers, e.g. via myrand.distribution().reset())
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void seed(int i)
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{
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global_rng.seed(i);
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}
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// uniform [0,1) or [a,b) distribution
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double uniform()
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{
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static boost::uniform_01<BOOST_RNG_ALGO&> myrand(global_rng);
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return myrand();
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}
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} // namespace
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} // namespace
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/* vim:set shiftwidth=4 softtabstop=4 expandtab: */
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