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+// mtrand.h
+// C++ include file for MT19937, with initialization improved 2002/1/26.
+// Coded by Takuji Nishimura and Makoto Matsumoto.
+// Ported to C++ by Jasper Bedaux 2003/1/1 (see http://www.bedaux.net/mtrand/).
+// The generators returning floating point numbers are based on
+// a version by Isaku Wada, 2002/01/09
+//
+// 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.keio.ac.jp/matumoto/emt.html
+// email: matumoto@math.keio.ac.jp
+//
+// Feedback about the C++ port should be sent to Jasper Bedaux,
+// see http://www.bedaux.net/mtrand/ for e-mail address and info.
+
+#ifndef MTRAND_H
+#define MTRAND_H
+
+class MTRand_int32 { // Mersenne Twister random number generator
+public:
+// default constructor: uses default seed only if this is the first instance
+ MTRand_int32() { if (!init) seed(5489UL); init = true; }
+// constructor with 32 bit int as seed
+ MTRand_int32(unsigned long s) { seed(s); init = true; }
+// constructor with array of size 32 bit ints as seed
+ MTRand_int32(const unsigned long* array, int size) { seed(array, size); init = true; }
+// the two seed functions
+ void seed(unsigned long); // seed with 32 bit integer
+ void seed(const unsigned long*, int size); // seed with array
+// overload operator() to make this a generator (functor)
+ unsigned long operator()() { return rand_int32(); }
+// 2007-02-11: made the destructor virtual; thanks "double more" for pointing this out
+ virtual ~MTRand_int32() {} // destructor
+protected: // used by derived classes, otherwise not accessible; use the ()-operator
+ unsigned long rand_int32(); // generate 32 bit random integer
+private:
+ static const int n = 624, m = 397; // compile time constants
+// the variables below are static (no duplicates can exist)
+ static unsigned long state[n]; // state vector array
+ static int p; // position in state array
+ static bool init; // true if init function is called
+// private functions used to generate the pseudo random numbers
+ unsigned long twiddle(unsigned long, unsigned long); // used by gen_state()
+ void gen_state(); // generate new state
+// make copy constructor and assignment operator unavailable, they don't make sense
+ MTRand_int32(const MTRand_int32&); // copy constructor not defined
+ void operator=(const MTRand_int32&); // assignment operator not defined
+};
+
+// inline for speed, must therefore reside in header file
+inline unsigned long MTRand_int32::twiddle(unsigned long u, unsigned long v) {
+ return (((u & 0x80000000UL) | (v & 0x7FFFFFFFUL)) >> 1)
+ ^ ((v & 1UL) * 0x9908B0DFUL);
+// 2013-07-22: line above modified for performance according to http://www.math.sci.hiroshima-u.ac.jp/~m-mat/MT/Ierymenko.html
+// thanks Vitaliy FEOKTISTOV for pointing this out
+}
+
+inline unsigned long MTRand_int32::rand_int32() { // generate 32 bit random int
+ if (p == n) gen_state(); // new state vector needed
+// gen_state() is split off to be non-inline, because it is only called once
+// in every 624 calls and otherwise irand() would become too big to get inlined
+ unsigned long x = state[p++];
+ x ^= (x >> 11);
+ x ^= (x << 7) & 0x9D2C5680UL;
+ x ^= (x << 15) & 0xEFC60000UL;
+ return x ^ (x >> 18);
+}
+
+// generates double floating point numbers in the half-open interval [0, 1)
+class MTRand : public MTRand_int32 {
+public:
+ MTRand() : MTRand_int32() {}
+ MTRand(unsigned long seed) : MTRand_int32(seed) {}
+ MTRand(const unsigned long* seed, int size) : MTRand_int32(seed, size) {}
+ ~MTRand() {}
+ double operator()() {
+ return static_cast<double>(rand_int32()) * (1. / 4294967296.); } // divided by 2^32
+private:
+ MTRand(const MTRand&); // copy constructor not defined
+ void operator=(const MTRand&); // assignment operator not defined
+};
+
+// generates double floating point numbers in the closed interval [0, 1]
+class MTRand_closed : public MTRand_int32 {
+public:
+ MTRand_closed() : MTRand_int32() {}
+ MTRand_closed(unsigned long seed) : MTRand_int32(seed) {}
+ MTRand_closed(const unsigned long* seed, int size) : MTRand_int32(seed, size) {}
+ ~MTRand_closed() {}
+ double operator()() {
+ return static_cast<double>(rand_int32()) * (1. / 4294967295.); } // divided by 2^32 - 1
+private:
+ MTRand_closed(const MTRand_closed&); // copy constructor not defined
+ void operator=(const MTRand_closed&); // assignment operator not defined
+};
+
+// generates double floating point numbers in the open interval (0, 1)
+class MTRand_open : public MTRand_int32 {
+public:
+ MTRand_open() : MTRand_int32() {}
+ MTRand_open(unsigned long seed) : MTRand_int32(seed) {}
+ MTRand_open(const unsigned long* seed, int size) : MTRand_int32(seed, size) {}
+ ~MTRand_open() {}
+ double operator()() {
+ return (static_cast<double>(rand_int32()) + .5) * (1. / 4294967296.); } // divided by 2^32
+private:
+ MTRand_open(const MTRand_open&); // copy constructor not defined
+ void operator=(const MTRand_open&); // assignment operator not defined
+};
+
+// generates 53 bit resolution doubles in the half-open interval [0, 1)
+class MTRand53 : public MTRand_int32 {
+public:
+ MTRand53() : MTRand_int32() {}
+ MTRand53(unsigned long seed) : MTRand_int32(seed) {}
+ MTRand53(const unsigned long* seed, int size) : MTRand_int32(seed, size) {}
+ ~MTRand53() {}
+ double operator()() {
+ return (static_cast<double>(rand_int32() >> 5) * 67108864. +
+ static_cast<double>(rand_int32() >> 6)) * (1. / 9007199254740992.); }
+private:
+ MTRand53(const MTRand53&); // copy constructor not defined
+ void operator=(const MTRand53&); // assignment operator not defined
+};
+
+#endif // MTRAND_H \ No newline at end of file