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mt19937ar.c
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1 //
2 // A C-program for MT19937, with initialization improved 2002/1/26.
3 // Coded by Takuji Nishimura and Makoto Matsumoto.
4 //
5 // Before using, initialize the state by using init_genrand(seed)
6 // or init_by_array(init_key, key_length).
7 //
8 // Copyright (C) 1997 - 2002, Makoto Matsumoto and Takuji Nishimura,
9 // All rights reserved.
10 // Copyright (C) 2005, Mutsuo Saito,
11 // All rights reserved.
12 //
13 // Redistribution and use in source and binary forms, with or without
14 // modification, are permitted provided that the following conditions
15 // are met:
16 //
17 // 1. Redistributions of source code must retain the above copyright
18 // notice, this list of conditions and the following disclaimer.
19 //
20 // 2. Redistributions in binary form must reproduce the above copyright
21 // notice, this list of conditions and the following disclaimer in the
22 // documentation and/or other materials provided with the distribution.
23 //
24 // 3. The names of its contributors may not be used to endorse or promote
25 // products derived from this software without specific prior written
26 // permission.
27 //
28 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
29 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
30 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
31 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
32 // CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
33 // EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
34 // PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
35 // PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
36 // LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
37 // NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
38 // SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
39 //
40 //
41 // Any feedback is very welcome.
42 // http://www.math.sci.hiroshima-u.ac.jp/~m-mat/MT/emt.html
43 // email: m-mat @ math.sci.hiroshima-u.ac.jp (remove space)
44 //
45 
50 
51 #include <stdio.h>
52 #include "mt19937ar.h"
53 
54 // Period parameters
55 #define N 624
56 #define M 397
57 #define MATRIX_A 0x9908b0dfUL // constant vector a
58 #define UPPER_MASK 0x80000000UL // most significant w-r bits
59 #define LOWER_MASK 0x7fffffffUL // least significant r bits
60 
61 static unsigned long mt[N]; // the array for the state vector
62 static int mti = N + 1; // mti==N+1 means mt[N] is not initialized
63 
68 void init_genrand( unsigned long s )
69 {
70  mt[0] = s & 0xffffffffUL;
71  for ( mti = 1; mti < N; mti++ )
72  {
73  mt[mti] =
74  ( 1812433253UL * ( mt[mti - 1] ^ ( mt[mti - 1] >> 30 ) ) + (unsigned long) mti );
75  // See Knuth TAOCP Vol2. 3rd Ed. P.106 for multiplier.
76  // In the previous versions, MSBs of the seed affect
77  // only MSBs of the array mt[].
78  // 2002/01/09 modified by Makoto Matsumoto
79  mt[mti] &= 0xffffffffUL;
80  // for >32 bit machines
81  }
82 }
83 
90 void init_by_array( unsigned long init_key[], int key_length )
91 {
92  int i, j, k;
93  init_genrand( 19650218UL );
94  i = 1; j = 0;
95  k = ( N > key_length ? N : key_length );
96  for (; k; k-- )
97  {
98  mt[i] = ( mt[i] ^ ( ( mt[i - 1] ^ ( mt[i - 1] >> 30 ) ) * 1664525UL ) )
99  + init_key[j] + (unsigned long) j; // non linear
100  mt[i] &= 0xffffffffUL; // for WORDSIZE > 32 machines
101  i++; j++;
102  if ( i >= N )
103  {
104  mt[0] = mt[N - 1]; i = 1;
105  }
106  if ( j >= key_length )
107  j = 0;
108  }
109  for ( k = N - 1; k; k-- )
110  {
111  mt[i] = ( mt[i] ^ ( ( mt[i - 1] ^ ( mt[i - 1] >> 30 ) ) * 1566083941UL ) )
112  - (unsigned long) i; // non linear
113  mt[i] &= 0xffffffffUL; // for WORDSIZE > 32 machines
114  i++;
115  if ( i >= N )
116  {
117  mt[0] = mt[N - 1]; i = 1;
118  }
119  }
120 
121  mt[0] = 0x80000000UL; // MSB is 1; assuring non-zero initial array
122 }
123 
128 unsigned long genrand_int32( void )
129 {
130  unsigned long y;
131  static unsigned long mag01[2] = { 0x0UL, MATRIX_A };
132  // mag01[x] = x * MATRIX_A for x=0,1
133 
134  if ( mti >= N ) // generate N words at one time
135  {
136  int kk;
137 
138  if ( mti == N + 1 ) // if init_genrand() has not been called,
139  init_genrand( 5489UL ); // a default initial seed is used
140 
141  for ( kk = 0; kk < N - M; kk++ )
142  {
143  y = ( mt[kk] & UPPER_MASK ) | ( mt[kk + 1] & LOWER_MASK );
144  mt[kk] = mt[kk + M] ^ ( y >> 1 ) ^ mag01[y & 0x1UL];
145  }
146  for (; kk < N - 1; kk++ )
147  {
148  y = ( mt[kk] & UPPER_MASK ) | ( mt[kk + 1] & LOWER_MASK );
149  mt[kk] = mt[kk + ( M - N )] ^ ( y >> 1 ) ^ mag01[y & 0x1UL];
150  }
151  y = ( mt[N - 1] & UPPER_MASK ) | ( mt[0] & LOWER_MASK );
152  mt[N - 1] = mt[M - 1] ^ ( y >> 1 ) ^ mag01[y & 0x1UL];
153 
154  mti = 0;
155  }
156 
157  y = mt[mti++];
158 
159  // Tempering
160  y ^= ( y >> 11 );
161  y ^= ( y << 7 ) & 0x9d2c5680UL;
162  y ^= ( y << 15 ) & 0xefc60000UL;
163  y ^= ( y >> 18 );
164 
165  return y;
166 }
167 
172 long genrand_int31( void )
173 {
174  return (long) ( genrand_int32() >> 1 );
175 }
176 
181 double genrand_real1( void )
182 {
183  return (double) genrand_int32() * ( 1.0 / 4294967295.0 );
184  // divided by 2^32-1
185 }
186 
191 double genrand_real2( void )
192 {
193  return (double) genrand_int32() * ( 1.0 / 4294967296.0 );
194  // divided by 2^32
195 }
196 
201 double genrand_real3( void )
202 {
203  return ( ( (double) genrand_int32() ) + 0.5 ) * ( 1.0 / 4294967296.0 );
204  // divided by 2^32
205 }
206 
211 double genrand_res53( void )
212 {
213  unsigned long a = genrand_int32() >> 5, b = genrand_int32() >> 6;
214  return ( (double) a * 67108864.0 + (double) b ) * ( 1.0 / 9007199254740992.0 );
215 }
216 // These real versions are due to Isaku Wada, 2002/01/09 added