/usr/include/libcoyotl/prng.h is in libcoyotl-dev 3.1.0-6ubuntu1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 | //---------------------------------------------------------------------
// Algorithmic Conjurings @ http://www.coyotegulch.com
//
// prng.h (libcoyotl)
//
// A Framework for Pseudorandom Number Generators
//---------------------------------------------------------------------
//
// Copyright 1990-2005 Scott Robert Ladd
//
// This program is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation; either version 2 of the License, or
// (at your option) any later version.
//
// This program 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 General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the
// Free Software Foundation, Inc.
// 59 Temple Place - Suite 330
// Boston, MA 02111-1307, USA.
//
//-----------------------------------------------------------------------
//
// For more information on this software package, please visit
// Scott's web site, Coyote Gulch Productions, at:
//
// http://www.coyotegulch.com
//
//-----------------------------------------------------------------------
#if !defined(LIBCOYOTL_PRNG_H)
#define LIBCOYOTL_PRNG_H
// Standard C Library
#include <cstddef>
#include <cstdio>
#include <ctime>
#include <cmath>
#include <fcntl.h>
#include <stdint.h>
namespace libcoyotl
{
//! An abstract definition of a peudorandom number generator
/*!
This class defines the generic properties of any psuedo-random number
generator that returns a 32-bit unsigned result.
*/
class prng
{
protected:
//! Initialization seed
uint32_t m_seed;
public:
//! Default constructor, reading seed from/dev/urandom or the time.
/*!
The constructor initializes the prng seed from either the time
or some stochastic source such as /dev/random or /dev/urandom.
*/
prng();
//! Default constructor, with optional seed.
/*!
Starts the PRNG with a specific seed; this is provided so that
a given sequence of "random" values can be duplicated. Note that
the actual sequence is predicated on the specific PRNG algorithm.
\param seed - Seed value used to "start" or seed the generator
*/
prng(uint32_t seed);
//! Initializes the generator with "seed"
/*!
Resets the generator using the provided seed value.
\param seed - Seed value used to "start" or seed the generator
*/
virtual void init(uint32_t seed);
//! Returns the original seed value
/*!
Returns the seed value used to initialize this generator.
\return The seed value used to initialize this generator
*/
uint32_t get_seed();
//! Get the next integer
/*!
Returns the next uint32_t in sequence.
\return A pseudorandom uint32_t value
*/
virtual uint32_t get_rand() = 0;
//! Get the next integer in the range [lo,hi]
/*!
Returns the next int_value between lo and hi, inclusive.
\param lo - Minimum value of result
\param hi - Maximum value of result
\return A pseudorandom uint32_t value
*/
uint32_t get_rand_range(uint32_t lo, uint32_t hi);
//! Get the next random value as a size_t index
/*!
Returns the next value as a size_t "index" in the range [0,length).
\param length - Maximum value of result
\return A pseudorandom size_t value
*/
size_t get_rand_index(size_t length);
//! Get the next number in the range [0,1]
/*!
Returns the next real number in the range [0,1], i.e., a number
greater than or equal to 0 and less than or equal to 1.
Provides 32-bit precision.
\return A pseudorandom double value
*/
double get_rand_real1();
//! Get the next number in the range [0,1)
/*!
Returns the next real number in the range [0,1), i.e., a number
greater than or equal to 0 and less than 1.
Provides 32-bit precision.
\return A pseudorandom double value
*/
double get_rand_real2();
//! Get the next number in the range (0,1)
/*!
Returns the next real number in the range (0,1), i.e., a number
greater than 0 and less than 1.
Provides 32-bit precision.
\return A pseudorandom double value
*/
double get_rand_real3();
//! Get the next number in the range [0,1)
/*!
Returns the next real number in the range [0,1), i.e., a number
greater than or equal to 0 and less than 1.
Provides 53-bit precision.
\return A pseudorandom double value
*/
double get_rand_real53();
};
//---------------------------------------------------------------------------
// Returns the original seed value
inline uint32_t prng::get_seed()
{
return m_seed;
}
//---------------------------------------------------------------------------
// Obtain a psuedorandom integer in the range [lo,hi]
inline uint32_t prng::get_rand_range(uint32_t lo, uint32_t hi)
{
// Local working storage
double range = hi - lo + 1.0;
// Use real value to caluclate range
return lo + uint32_t(floor(range * get_rand_real2()));
}
//--------------------------------------------------------------------------
// Returns the next value as a size_t "index" in the range [0,length).
inline size_t prng::get_rand_index(size_t length)
{
return size_t(double(length) * get_rand_real2());
}
//--------------------------------------------------------------------------
// Obtain a psuedorandom real number in the range [0,1], i.e., a number
// greater than or equal to 0 and less than or equal to 1.
inline double prng::get_rand_real1()
{
// privides a granularity of approx. 2.3E-10
return double(get_rand()) * (1.0 / 4294967295.0);
}
//--------------------------------------------------------------------------
// Obtain a psuedorandom real number in the range [0,1), i.e., a number
// greater than or equal to 0 and less than 1.
inline double prng::get_rand_real2()
{
// privides a granularity of approx. 2.3E-10
return double(get_rand()) * (1.0 / 4294967296.0);
}
//--------------------------------------------------------------------------
// Obtain a psuedorandom real number in the range (0,1), i.e., a number
// greater than 0 and less than 1.
inline double prng::get_rand_real3()
{
// privides a granularity of approx. 2.3E-10
return double((double(get_rand()) + 0.5) * (1.0 / 4294967296.0));
}
} // end namespace libcoyotl
#endif
|