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285 lines
11 KiB
285 lines
11 KiB
// this program is a JavaScript version of Mersenne Twister, with concealment and encapsulation in class, |
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// an almost straight conversion from the original program, mt19937ar.c, |
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// translated by y. okada on July 17, 2006. |
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// and modified a little at july 20, 2006, but there are not any substantial differences. |
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// in this program, procedure descriptions and comments of original source code were not removed. |
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// lines commented with //c// were originally descriptions of c procedure. and a few following lines are appropriate JavaScript descriptions. |
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// lines commented with /* and */ are original comments. |
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// lines commented with // are additional comments in this JavaScript version. |
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// before using this version, create at least one instance of MersenneTwister19937 class, and initialize the each state, given below in c comments, of all the instances. |
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/* |
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A C-program for MT19937, with initialization improved 2002/1/26. |
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Coded by Takuji Nishimura and Makoto Matsumoto. |
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Before using, initialize the state by using init_genrand(seed) |
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or init_by_array(init_key, key_length). |
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Copyright (C) 1997 - 2002, Makoto Matsumoto and Takuji Nishimura, |
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All rights reserved. |
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Redistribution and use in source and binary forms, with or without |
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modification, are permitted provided that the following conditions |
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are met: |
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1. Redistributions of source code must retain the above copyright |
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notice, this list of conditions and the following disclaimer. |
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2. Redistributions in binary form must reproduce the above copyright |
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notice, this list of conditions and the following disclaimer in the |
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documentation and/or other materials provided with the distribution. |
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3. The names of its contributors may not be used to endorse or promote |
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products derived from this software without specific prior written |
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permission. |
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THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
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"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
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LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
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A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR |
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CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, |
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EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, |
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PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR |
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PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF |
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LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING |
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NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS |
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SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
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Any feedback is very welcome. |
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http://www.math.sci.hiroshima-u.ac.jp/~m-mat/MT/emt.html |
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email: m-mat @ math.sci.hiroshima-u.ac.jp (remove space) |
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*/ |
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function MersenneTwister19937() |
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{ |
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/* constants should be scoped inside the class */ |
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var N, M, MATRIX_A, UPPER_MASK, LOWER_MASK; |
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/* Period parameters */ |
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//c//#define N 624 |
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//c//#define M 397 |
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//c//#define MATRIX_A 0x9908b0dfUL /* constant vector a */ |
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//c//#define UPPER_MASK 0x80000000UL /* most significant w-r bits */ |
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//c//#define LOWER_MASK 0x7fffffffUL /* least significant r bits */ |
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N = 624; |
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M = 397; |
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MATRIX_A = 0x9908b0df; /* constant vector a */ |
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UPPER_MASK = 0x80000000; /* most significant w-r bits */ |
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LOWER_MASK = 0x7fffffff; /* least significant r bits */ |
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//c//static unsigned long mt[N]; /* the array for the state vector */ |
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//c//static int mti=N+1; /* mti==N+1 means mt[N] is not initialized */ |
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var mt = new Array(N); /* the array for the state vector */ |
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var mti = N+1; /* mti==N+1 means mt[N] is not initialized */ |
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function unsigned32 (n1) // returns a 32-bits unsiged integer from an operand to which applied a bit operator. |
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{ |
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return n1 < 0 ? (n1 ^ UPPER_MASK) + UPPER_MASK : n1; |
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} |
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function subtraction32 (n1, n2) // emulates lowerflow of a c 32-bits unsiged integer variable, instead of the operator -. these both arguments must be non-negative integers expressible using unsigned 32 bits. |
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{ |
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return n1 < n2 ? unsigned32((0x100000000 - (n2 - n1)) & 0xffffffff) : n1 - n2; |
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} |
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function addition32 (n1, n2) // emulates overflow of a c 32-bits unsiged integer variable, instead of the operator +. these both arguments must be non-negative integers expressible using unsigned 32 bits. |
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{ |
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return unsigned32((n1 + n2) & 0xffffffff) |
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} |
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function multiplication32 (n1, n2) // emulates overflow of a c 32-bits unsiged integer variable, instead of the operator *. these both arguments must be non-negative integers expressible using unsigned 32 bits. |
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{ |
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var sum = 0; |
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for (var i = 0; i < 32; ++i){ |
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if ((n1 >>> i) & 0x1){ |
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sum = addition32(sum, unsigned32(n2 << i)); |
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} |
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} |
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return sum; |
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} |
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/* initializes mt[N] with a seed */ |
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//c//void init_genrand(unsigned long s) |
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this.init_genrand = function (s) |
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{ |
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//c//mt[0]= s & 0xffffffff; |
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mt[0]= unsigned32(s & 0xffffffff); |
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for (mti=1; mti<N; mti++) { |
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mt[mti] = |
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//c//(1812433253 * (mt[mti-1] ^ (mt[mti-1] >> 30)) + mti); |
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addition32(multiplication32(1812433253, unsigned32(mt[mti-1] ^ (mt[mti-1] >>> 30))), mti); |
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/* See Knuth TAOCP Vol2. 3rd Ed. P.106 for multiplier. */ |
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/* In the previous versions, MSBs of the seed affect */ |
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/* only MSBs of the array mt[]. */ |
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/* 2002/01/09 modified by Makoto Matsumoto */ |
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//c//mt[mti] &= 0xffffffff; |
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mt[mti] = unsigned32(mt[mti] & 0xffffffff); |
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/* for >32 bit machines */ |
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} |
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} |
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/* initialize by an array with array-length */ |
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/* init_key is the array for initializing keys */ |
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/* key_length is its length */ |
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/* slight change for C++, 2004/2/26 */ |
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//c//void init_by_array(unsigned long init_key[], int key_length) |
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this.init_by_array = function (init_key, key_length) |
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{ |
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//c//int i, j, k; |
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var i, j, k; |
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//c//init_genrand(19650218); |
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this.init_genrand(19650218); |
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i=1; j=0; |
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k = (N>key_length ? N : key_length); |
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for (; k; k--) { |
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//c//mt[i] = (mt[i] ^ ((mt[i-1] ^ (mt[i-1] >> 30)) * 1664525)) |
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//c// + init_key[j] + j; /* non linear */ |
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mt[i] = addition32(addition32(unsigned32(mt[i] ^ multiplication32(unsigned32(mt[i-1] ^ (mt[i-1] >>> 30)), 1664525)), init_key[j]), j); |
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mt[i] = |
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//c//mt[i] &= 0xffffffff; /* for WORDSIZE > 32 machines */ |
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unsigned32(mt[i] & 0xffffffff); |
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i++; j++; |
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if (i>=N) { mt[0] = mt[N-1]; i=1; } |
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if (j>=key_length) j=0; |
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} |
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for (k=N-1; k; k--) { |
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//c//mt[i] = (mt[i] ^ ((mt[i-1] ^ (mt[i-1] >> 30)) * 1566083941)) |
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//c//- i; /* non linear */ |
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mt[i] = subtraction32(unsigned32((dbg=mt[i]) ^ multiplication32(unsigned32(mt[i-1] ^ (mt[i-1] >>> 30)), 1566083941)), i); |
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//c//mt[i] &= 0xffffffff; /* for WORDSIZE > 32 machines */ |
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mt[i] = unsigned32(mt[i] & 0xffffffff); |
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i++; |
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if (i>=N) { mt[0] = mt[N-1]; i=1; } |
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} |
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mt[0] = 0x80000000; /* MSB is 1; assuring non-zero initial array */ |
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} |
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/* moved outside of genrand_int32() by jwatte 2010-11-17; generate less garbage */ |
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var mag01 = [0x0, MATRIX_A]; |
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/* generates a random number on [0,0xffffffff]-interval */ |
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//c//unsigned long genrand_int32(void) |
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this.genrand_int32 = function () |
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{ |
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//c//unsigned long y; |
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//c//static unsigned long mag01[2]={0x0UL, MATRIX_A}; |
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var y; |
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/* mag01[x] = x * MATRIX_A for x=0,1 */ |
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if (mti >= N) { /* generate N words at one time */ |
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//c//int kk; |
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var kk; |
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if (mti == N+1) /* if init_genrand() has not been called, */ |
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//c//init_genrand(5489); /* a default initial seed is used */ |
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this.init_genrand(5489); /* a default initial seed is used */ |
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for (kk=0;kk<N-M;kk++) { |
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//c//y = (mt[kk]&UPPER_MASK)|(mt[kk+1]&LOWER_MASK); |
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//c//mt[kk] = mt[kk+M] ^ (y >> 1) ^ mag01[y & 0x1]; |
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y = unsigned32((mt[kk]&UPPER_MASK)|(mt[kk+1]&LOWER_MASK)); |
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mt[kk] = unsigned32(mt[kk+M] ^ (y >>> 1) ^ mag01[y & 0x1]); |
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} |
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for (;kk<N-1;kk++) { |
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//c//y = (mt[kk]&UPPER_MASK)|(mt[kk+1]&LOWER_MASK); |
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//c//mt[kk] = mt[kk+(M-N)] ^ (y >> 1) ^ mag01[y & 0x1]; |
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y = unsigned32((mt[kk]&UPPER_MASK)|(mt[kk+1]&LOWER_MASK)); |
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mt[kk] = unsigned32(mt[kk+(M-N)] ^ (y >>> 1) ^ mag01[y & 0x1]); |
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} |
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//c//y = (mt[N-1]&UPPER_MASK)|(mt[0]&LOWER_MASK); |
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//c//mt[N-1] = mt[M-1] ^ (y >> 1) ^ mag01[y & 0x1]; |
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y = unsigned32((mt[N-1]&UPPER_MASK)|(mt[0]&LOWER_MASK)); |
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mt[N-1] = unsigned32(mt[M-1] ^ (y >>> 1) ^ mag01[y & 0x1]); |
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mti = 0; |
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} |
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y = mt[mti++]; |
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/* Tempering */ |
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//c//y ^= (y >> 11); |
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//c//y ^= (y << 7) & 0x9d2c5680; |
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//c//y ^= (y << 15) & 0xefc60000; |
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//c//y ^= (y >> 18); |
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y = unsigned32(y ^ (y >>> 11)); |
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y = unsigned32(y ^ ((y << 7) & 0x9d2c5680)); |
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y = unsigned32(y ^ ((y << 15) & 0xefc60000)); |
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y = unsigned32(y ^ (y >>> 18)); |
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return y; |
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} |
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/* generates a random number on [0,0x7fffffff]-interval */ |
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//c//long genrand_int31(void) |
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this.genrand_int31 = function () |
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{ |
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//c//return (genrand_int32()>>1); |
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return (this.genrand_int32()>>>1); |
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} |
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/* generates a random number on [0,1]-real-interval */ |
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//c//double genrand_real1(void) |
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this.genrand_real1 = function () |
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{ |
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//c//return genrand_int32()*(1.0/4294967295.0); |
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return this.genrand_int32()*(1.0/4294967295.0); |
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/* divided by 2^32-1 */ |
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} |
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/* generates a random number on [0,1)-real-interval */ |
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//c//double genrand_real2(void) |
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this.genrand_real2 = function () |
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{ |
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//c//return genrand_int32()*(1.0/4294967296.0); |
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return this.genrand_int32()*(1.0/4294967296.0); |
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/* divided by 2^32 */ |
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} |
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/* generates a random number on (0,1)-real-interval */ |
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//c//double genrand_real3(void) |
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this.genrand_real3 = function () |
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{ |
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//c//return ((genrand_int32()) + 0.5)*(1.0/4294967296.0); |
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return ((this.genrand_int32()) + 0.5)*(1.0/4294967296.0); |
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/* divided by 2^32 */ |
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} |
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/* generates a random number on [0,1) with 53-bit resolution*/ |
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//c//double genrand_res53(void) |
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this.genrand_res53 = function () |
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{ |
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//c//unsigned long a=genrand_int32()>>5, b=genrand_int32()>>6; |
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var a=this.genrand_int32()>>>5, b=this.genrand_int32()>>>6; |
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return(a*67108864.0+b)*(1.0/9007199254740992.0); |
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} |
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/* These real versions are due to Isaku Wada, 2002/01/09 added */ |
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} |
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// Exports: Public API |
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// Export the twister class |
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exports.MersenneTwister19937 = MersenneTwister19937; |
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// Export a simplified function to generate random numbers |
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var gen = new MersenneTwister19937; |
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gen.init_genrand((new Date).getTime() % 1000000000); |
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exports.rand = function(N) { |
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if (!N) |
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{ |
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N = 32768; |
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} |
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return Math.floor(gen.genrand_real2() * N); |
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} |
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exports.seed = function(S) { |
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if (typeof(S) != 'number') |
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{ |
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throw new Error("seed(S) must take numeric argument; is " + typeof(S)); |
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} |
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gen.init_genrand(S); |
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} |
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exports.seed_array = function(A) { |
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if (typeof(A) != 'object') |
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{ |
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throw new Error("seed_array(A) must take array of numbers; is " + typeof(A)); |
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} |
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gen.init_by_array(A); |
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} |
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