uint64 state;
};
+/*!
+ Random Number Generator - MT
+
+ The class implements RNG using the Mersenne Twister algorithm
+*/
+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
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. */
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]);
+ }
+}