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add Mersenne Twister random number generator

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marina.kolpakova 2013-03-06 02:51:19 +04:00
parent 6569a58518
commit 12fe6ff734
3 changed files with 180 additions and 0 deletions
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29
modules/core/include/opencv2/core/core.hpp
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@ -2014,6 +2014,35 @@ public:
uint64 state; uint64 state;
}; };
class CV_EXPORTS RNG_MT19937
{
public:
RNG_MT19937();
RNG_MT19937(unsigned s);
void seed(unsigned s);
unsigned next();
operator int();
operator unsigned();
operator float();
operator double();
unsigned operator ()(unsigned N);
unsigned operator ()();
// returns uniformly distributed integer random number from [a,b) range
int uniform(int a, int b);
// returns uniformly distributed floating-point random number from [a,b) range
float uniform(float a, float b);
// returns uniformly distributed double-precision floating-point random number from [a,b) range
double uniform(double a, double b);
private:
enum PeriodParameters {N = 624, M = 397};
unsigned state[N];
int mti;
};
/*! /*!
Termination criteria in iterative algorithms Termination criteria in iterative algorithms

125
modules/core/src/rand.cpp
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@ -883,4 +883,129 @@ CV_IMPL void cvRandShuffle( CvArr* arr, CvRNG* _rng, double iter_factor )
cv::randShuffle( dst, iter_factor, &rng ); cv::randShuffle( dst, iter_factor, &rng );
} }
// Mersenne Twister random number generator.
// Inspired by http://www.math.sci.hiroshima-u.ac.jp/~m-mat/MT/MT2002/CODES/mt19937ar.c
/*
A C-program for MT19937, with initialization improved 2002/1/26.
Coded by Takuji Nishimura and Makoto Matsumoto.
Before using, initialize the state by using init_genrand(seed)
or init_by_array(init_key, key_length).
Copyright (C) 1997 - 2002, Makoto Matsumoto and Takuji Nishimura,
All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions
are met:
1. Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
2. Redistributions in binary form must reproduce the above copyright
notice, this list of conditions and the following disclaimer in the
documentation and/or other materials provided with the distribution.
3. The names of its contributors may not be used to endorse or promote
products derived from this software without specific prior written
permission.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
Any feedback is very welcome.
http://www.math.sci.hiroshima-u.ac.jp/~m-mat/MT/emt.html
email: m-mat @ math.sci.hiroshima-u.ac.jp (remove space)
*/
cv::RNG_MT19937::RNG_MT19937(unsigned s) { seed(s); }
cv::RNG_MT19937::RNG_MT19937() { seed(5489U); }
void cv::RNG_MT19937::seed(unsigned s)
{
state[0]= s;
for (mti = 1; mti < N; mti++)
{
/* See Knuth TAOCP Vol2. 3rd Ed. P.106 for multiplier. */
state[mti] = (1812433253U * (state[mti - 1] ^ (state[mti - 1] >> 30)) + mti);
}
}
unsigned cv::RNG_MT19937::next()
{
/* mag01[x] = x * MATRIX_A for x=0,1 */
static unsigned mag01[2] = { 0x0U, /*MATRIX_A*/ 0x9908b0dfU};
const unsigned UPPER_MASK = 0x80000000U;
const unsigned LOWER_MASK = 0x7fffffffU;
/* generate N words at one time */
if (mti >= N)
{
int kk = 0;
for (; kk < N - M; ++kk)
{
unsigned y = (state[kk] & UPPER_MASK) | (state[kk + 1] & LOWER_MASK);
state[kk] = state[kk + M] ^ (y >> 1) ^ mag01[y & 0x1U];
}
for (; kk < N - 1; ++kk)
{
unsigned y = (state[kk] & UPPER_MASK) | (state[kk + 1] & LOWER_MASK);
state[kk] = state[kk + (M - N)] ^ (y >> 1) ^ mag01[y & 0x1U];
}
unsigned y = (state[N - 1] & UPPER_MASK) | (state[0] & LOWER_MASK);
state[N - 1] = state[M - 1] ^ (y >> 1) ^ mag01[y & 0x1U];
mti = 0;
}
unsigned y = state[mti++];
/* Tempering */
y ^= (y >> 11);
y ^= (y << 7) & 0x9d2c5680U;
y ^= (y << 15) & 0xefc60000U;
y ^= (y >> 18);
return y;
}
cv::RNG_MT19937::operator unsigned() { return next(); }
cv::RNG_MT19937::operator int() { return (int)next();}
cv::RNG_MT19937::operator float() { return next() * (1.f / 4294967296.f); }
cv::RNG_MT19937::operator double()
{
unsigned a = next() >> 5;
unsigned b = next() >> 6;
return (a * 67108864.0 + b) * (1.0 / 9007199254740992.0);
}
int cv::RNG_MT19937::uniform(int a, int b) { return (int)(next() % (b - a) + a); }
float cv::RNG_MT19937::uniform(float a, float b) { return ((float)*this)*(b - a) + a; }
double cv::RNG_MT19937::uniform(double a, double b) { return ((double)*this)*(b - a) + a; }
unsigned cv::RNG_MT19937::operator ()(unsigned b) { return next() % b; }
unsigned cv::RNG_MT19937::operator ()() { return next(); }
/* End of file. */ /* End of file. */

26
modules/core/test/test_rand.cpp
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@ -339,3 +339,29 @@ protected:
TEST(Core_Rand, range) { Core_RandRangeTest test; test.safe_run(); } TEST(Core_Rand, range) { Core_RandRangeTest test; test.safe_run(); }
TEST(Core_RNG_MT19937, regression)
{
cv::RNG_MT19937 rng;
int actual[61] = {0, };
const size_t length = (sizeof(actual) / sizeof(actual[0]));
for (int i = 0; i < 10000; ++i )
{
actual[(unsigned)(rng.next() ^ i) % length]++;
}
int expected[length] = {
177, 158, 180, 177, 160, 179, 143, 162,
177, 144, 170, 174, 165, 168, 168, 156,
177, 157, 159, 169, 177, 182, 166, 154,
144, 180, 168, 152, 170, 187, 160, 145,
139, 164, 157, 179, 148, 183, 159, 160,
196, 184, 149, 142, 162, 148, 163, 152,
168, 173, 160, 181, 172, 181, 155, 153,
158, 171, 138, 150, 150 };
for (size_t i = 0; i < length; ++i)
{
ASSERT_EQ(expected[i], actual[i]);
}
}