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75 lines
1.9 KiB
75 lines
1.9 KiB
//==============================================================================
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//
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// Copyright (c) 2002-
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// Authors:
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// * Dave Parker <david.parker@comlab.ox.ac.uk> (University of Oxford)
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//
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//------------------------------------------------------------------------------
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//
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// This file is part of PRISM.
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//
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// PRISM is free software; you can redistribute it and/or modify
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// it under the terms of the GNU General Public License as published by
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// the Free Software Foundation; either version 2 of the License, or
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// (at your option) any later version.
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//
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// PRISM is distributed in the hope that it will be useful,
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// but WITHOUT ANY WARRANTY; without even the implied warranty of
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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// GNU General Public License for more details.
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//
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// You should have received a copy of the GNU General Public License
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// along with PRISM; if not, write to the Free Software Foundation,
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// Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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//
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//==============================================================================
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package simulator;
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import java.util.Random;
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public class RandomNumberGenerator
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{
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private Random random;
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public RandomNumberGenerator()
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{
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random = new Random();
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}
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/**
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* Pick a (uniformly) random integer in range [0,...,n-1].
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*/
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public int randomUnifInt(int n)
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{
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return random.nextInt(n);
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}
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/**
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* Pick a (uniformly) random double in range [0,1).
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*/
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public double randomUnifDouble()
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{
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return random.nextDouble();
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}
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/**
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* Pick a (uniformly) random double in range [0,x).
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*/
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public double randomUnifDouble(double x)
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{
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return x * random.nextDouble();
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}
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/**
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* Pick a random double according to exponential distribution with rate x.
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*/
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public double randomExpDouble(double x)
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{
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double y;
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// Pick (non-zero) random y in (0,1)
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while ((y = random.nextDouble()) == 0);
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// Sample exponential
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return (-Math.log(y)) / x;
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}
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}
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