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Diffstat (limited to 'numpy/random/mtrand/initarray.c')
| -rw-r--r-- | numpy/random/mtrand/initarray.c | 134 |
1 files changed, 134 insertions, 0 deletions
diff --git a/numpy/random/mtrand/initarray.c b/numpy/random/mtrand/initarray.c new file mode 100644 index 000000000..9bf0ef286 --- /dev/null +++ b/numpy/random/mtrand/initarray.c @@ -0,0 +1,134 @@ +/* These function have been adapted from Python 2.4.1's _randommodule.c + + The following changes have been made to it in 2005 by Robert Kern: + + * init_by_array has been declared extern, has a void return, and uses the + rk_state structure to hold its data. + + The original file has the following verbatim comments: + + ------------------------------------------------------------------ + The code in this module was based on a download from: + http://www.math.keio.ac.jp/~matumoto/MT2002/emt19937ar.html + + It was modified in 2002 by Raymond Hettinger as follows: + + * the principal computational lines untouched except for tabbing. + + * renamed genrand_res53() to random_random() and wrapped + in python calling/return code. + + * genrand_int32() and the helper functions, init_genrand() + and init_by_array(), were declared static, wrapped in + Python calling/return code. also, their global data + references were replaced with structure references. + + * unused functions from the original were deleted. + new, original C python code was added to implement the + Random() interface. + + The following are the verbatim comments from the original code: + + 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.keio.ac.jp/matumoto/emt.html + email: matumoto@math.keio.ac.jp +*/ + +#include "initarray.h" + +static void +init_genrand(rk_state *self, unsigned long s); + +/* initializes mt[RK_STATE_LEN] with a seed */ +static void +init_genrand(rk_state *self, unsigned long s) +{ + int mti; + unsigned long *mt; + + mt = self->key; + mt[0]= s & 0xffffffffUL; + for (mti=1; mti<RK_STATE_LEN; mti++) { + mt[mti] = + (1812433253UL * (mt[mti-1] ^ (mt[mti-1] >> 30)) + mti); + /* See Knuth TAOCP Vol2. 3rd Ed. P.106 for multiplier. */ + /* In the previous versions, MSBs of the seed affect */ + /* only MSBs of the array mt[]. */ + /* 2002/01/09 modified by Makoto Matsumoto */ + mt[mti] &= 0xffffffffUL; + /* for >32 bit machines */ + } + self->pos = mti; + return; +} + + +/* initialize by an array with array-length */ +/* init_key is the array for initializing keys */ +/* key_length is its length */ +extern void +init_by_array(rk_state *self, unsigned long init_key[], unsigned long key_length) +{ + unsigned int i, j, k; /* was signed in the original code. RDH 12/16/2002 */ + unsigned long *mt; + + mt = self->key; + init_genrand(self, 19650218UL); + i=1; j=0; + k = (RK_STATE_LEN>key_length ? RK_STATE_LEN : key_length); + for (; k; k--) { + mt[i] = (mt[i] ^ ((mt[i-1] ^ (mt[i-1] >> 30)) * 1664525UL)) + + init_key[j] + j; /* non linear */ + mt[i] &= 0xffffffffUL; /* for WORDSIZE > 32 machines */ + i++; j++; + if (i>=RK_STATE_LEN) { mt[0] = mt[RK_STATE_LEN-1]; i=1; } + if (j>=key_length) j=0; + } + for (k=RK_STATE_LEN-1; k; k--) { + mt[i] = (mt[i] ^ ((mt[i-1] ^ (mt[i-1] >> 30)) * 1566083941UL)) + - i; /* non linear */ + mt[i] &= 0xffffffffUL; /* for WORDSIZE > 32 machines */ + i++; + if (i>=RK_STATE_LEN) { mt[0] = mt[RK_STATE_LEN-1]; i=1; } + } + + mt[0] = 0x80000000UL; /* MSB is 1; assuring non-zero initial array */ +} + |