00001 /* 00002 A C-program for MT19937, with initialization improved 2002/1/26. 00003 Coded by Takuji Nishimura and Makoto Matsumoto. 00004 00005 Before using, initialize the state by using init_genrand(seed) 00006 or init_by_array(init_key, key_length). 00007 00008 Copyright (C) 1997 - 2002, Makoto Matsumoto and Takuji Nishimura, 00009 All rights reserved. 00010 Copyright (C) 2005, Mutsuo Saito, 00011 All rights reserved. 00012 00013 Redistribution and use in source and binary forms, with or without 00014 modification, are permitted provided that the following conditions 00015 are met: 00016 00017 1. Redistributions of source code must retain the above copyright 00018 notice, this list of conditions and the following disclaimer. 00019 00020 2. Redistributions in binary form must reproduce the above copyright 00021 notice, this list of conditions and the following disclaimer in the 00022 documentation and/or other materials provided with the distribution. 00023 00024 3. The names of its contributors may not be used to endorse or promote 00025 products derived from this software without specific prior written 00026 permission. 00027 00028 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 00029 "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 00030 LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 00031 A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR 00032 CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, 00033 EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, 00034 PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR 00035 PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF 00036 LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING 00037 NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS 00038 SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 00039 00040 00041 Any feedback is very welcome. 00042 http://www.math.sci.hiroshima-u.ac.jp/~m-mat/MT/emt.html 00043 email: m-mat @ math.sci.hiroshima-u.ac.jp (remove space) 00044 */ 00045 00046 #include "mt19937.hpp" 00047 00048 /* initializes mt[MT19937_N] with a seed */ 00049 mt19937::mt19937( unsigned long s ) 00050 { 00051 init( s ); 00052 } 00053 00054 /* initializes mt[MT19937_N] with a seed */ 00055 void mt19937::init( unsigned long s ) 00056 { 00057 mt[0]= s & 0xffffffffUL; 00058 for( mti=1; mti<MT19937_N; mti++ ) { 00059 mt[mti] = (1812433253UL * (mt[mti-1] ^ (mt[mti-1] >> 30)) + mti); 00060 /* See Knuth TAOCP Vol2. 3rd Ed. P.106 for multiplier. */ 00061 /* In the previous versions, MSBs of the seed affect */ 00062 /* only MSBs of the array mt[]. */ 00063 /* 2002/01/09 modified by Makoto Matsumoto */ 00064 mt[mti] &= 0xffffffffUL; 00065 /* for >32 bit machines */ 00066 } 00067 } 00068 00069 /* initialize by an array with array-length */ 00070 /* init_key is the array for initializing keys */ 00071 /* key_length is its length */ 00072 /* slight change for C++, 2004/2/26 */ 00073 mt19937::mt19937( unsigned long init_key[], int key_length ) 00074 { 00075 int i, j, k; 00076 00077 init( 19650218UL ); 00078 i=1; j=0; 00079 k = (MT19937_N>key_length ? MT19937_N : key_length); 00080 for (; k; k--) { 00081 mt[i] = (mt[i] ^ ((mt[i-1] ^ (mt[i-1] >> 30)) * 1664525UL)) 00082 + init_key[j] + j; /* non linear */ 00083 mt[i] &= 0xffffffffUL; /* for WORDSIZE > 32 machines */ 00084 i++; j++; 00085 if (i>=MT19937_N) { mt[0] = mt[MT19937_N-1]; i=1; } 00086 if (j>=key_length) j=0; 00087 } 00088 for (k=MT19937_N-1; k; k--) { 00089 mt[i] = (mt[i] ^ ((mt[i-1] ^ (mt[i-1] >> 30)) * 1566083941UL)) 00090 - i; /* non linear */ 00091 mt[i] &= 0xffffffffUL; /* for WORDSIZE > 32 machines */ 00092 i++; 00093 if (i>=MT19937_N) { mt[0] = mt[MT19937_N-1]; i=1; } 00094 } 00095 00096 mt[0] = 0x80000000UL; /* MSB is 1; assuring non-zero initial array */ 00097 } 00098 00099 /* generates a random number on [0,0xffffffff]-interval */ 00100 unsigned long mt19937::genrand_int32(void) 00101 { 00102 unsigned long y; 00103 static unsigned long mag01[2]={0x0UL, MT19937_MATRIX_A}; 00104 /* mag01[x] = x * MATRIX_A for x=0,1 */ 00105 00106 if (mti >= MT19937_N) { /* generate MT19937_N words at one time */ 00107 int kk; 00108 00109 if (mti == MT19937_N+1) /* if init_genrand() has not been called, */ 00110 init( 5489UL ); /* a default initial seed is used */ 00111 00112 for (kk=0;kk<MT19937_N-MT19937_M;kk++) { 00113 y = (mt[kk]&MT19937_UPPER_MASK)|(mt[kk+1]&MT19937_LOWER_MASK); 00114 mt[kk] = mt[kk+MT19937_M] ^ (y >> 1) ^ mag01[y & 0x1UL]; 00115 } 00116 for (;kk<MT19937_N-1;kk++) { 00117 y = (mt[kk]&MT19937_UPPER_MASK)|(mt[kk+1]&MT19937_LOWER_MASK); 00118 mt[kk] = mt[kk+(MT19937_M-MT19937_N)] ^ (y >> 1) ^ mag01[y & 0x1UL]; 00119 } 00120 y = (mt[MT19937_N-1]&MT19937_UPPER_MASK)|(mt[0]&MT19937_LOWER_MASK); 00121 mt[MT19937_N-1] = mt[MT19937_M-1] ^ (y >> 1) ^ mag01[y & 0x1UL]; 00122 00123 mti = 0; 00124 } 00125 00126 y = mt[mti++]; 00127 00128 /* Tempering */ 00129 y ^= (y >> 11); 00130 y ^= (y << 7) & 0x9d2c5680UL; 00131 y ^= (y << 15) & 0xefc60000UL; 00132 y ^= (y >> 18); 00133 00134 return y; 00135 } 00136 00137 /* generates a random number on [0,0x7fffffff]-interval */ 00138 long mt19937::genrand_int31(void) 00139 { 00140 return (long)(genrand_int32()>>1); 00141 } 00142 00143 /* generates a random number on [0,1]-real-interval */ 00144 double mt19937::genrand_real1( void ) 00145 { 00146 return genrand_int32()*(1.0/4294967295.0); 00147 /* divided by 2^32-1 */ 00148 } 00149 00150 /* generates a random number on [0,1)-real-interval */ 00151 double mt19937::genrand_real2(void) 00152 { 00153 return genrand_int32()*(1.0/4294967296.0); 00154 /* divided by 2^32 */ 00155 } 00156 00157 /* generates a random number on (0,1)-real-interval */ 00158 double mt19937::genrand_real3(void) 00159 { 00160 return (((double)genrand_int32()) + 0.5)*(1.0/4294967296.0); 00161 /* divided by 2^32 */ 00162 } 00163 00164 /* generates a random number on [0,1) with 53-bit resolution*/ 00165 double mt19937::genrand_res53(void) 00166 { 00167 unsigned long a=genrand_int32()>>5, b=genrand_int32()>>6; 00168 return(a*67108864.0+b)*(1.0/9007199254740992.0); 00169 } 00170 /* These real versions are due to Isaku Wada, 2002/01/09 added */