161a499c76
git-svn-id: https://svn.code.sf.net/p/rathena/svn/trunk@14865 54d463be-8e91-2dee-dedb-b68131a5f0ec
80 lines
2.9 KiB
Plaintext
80 lines
2.9 KiB
Plaintext
This is a Mersenne Twister pseudorandom number generator
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with period 2^19937-1 with improved initialization scheme,
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modified on 2002/1/26 by Takuji Nishimura and Makoto Matsumoto.
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modified on 2005/4/26 by Mutsuo Saito
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Contents of this tar ball:
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readme-mt.txt this file
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mt19937ar.c the C source (ar: initialize by ARray)
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mt19937ar.h the C header file for mt19937ar
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mtTest.c the C test main program of mt19937ar.c
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mt19937ar.out Test outputs of six types generators. 1000 for each
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1. Initialization
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The initialization scheme for the previous versions of MT
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(e.g. 1999/10/28 version or earlier) has a tiny problem, that
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the most significant bits of the seed is not well reflected
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to the state vector of MT.
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This version (2002/1/26) has two initialization schemes:
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init_genrand(seed) and init_by_array(init_key, key_length).
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init_genrand(seed) initializes the state vector by using
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one unsigned 32-bit integer "seed", which may be zero.
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init_by_array(init_key, key_length) initializes the state vector
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by using an array init_key[] of unsigned 32-bit integers
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of length key_kength. If key_length is smaller than 624,
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then each array of 32-bit integers gives distinct initial
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state vector. This is useful if you want a larger seed space
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than 32-bit word.
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2. Generation
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After initialization, the following type of pseudorandom numbers
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are available.
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genrand_int32() generates unsigned 32-bit integers.
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genrand_int31() generates unsigned 31-bit integers.
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genrand_real1() generates uniform real in [0,1] (32-bit resolution).
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genrand_real2() generates uniform real in [0,1) (32-bit resolution).
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genrand_real3() generates uniform real in (0,1) (32-bit resolution).
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genrand_res53() generates uniform real in [0,1) with 53-bit resolution.
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Note: the last five functions call the first one.
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if you need more speed for these five functions, you may
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suppress the function call by copying genrand_int32() and
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replacing the last return(), following to these five functions.
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3. main()
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main() is an example to initialize with an array of length 4,
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then 1000 outputs of unsigned 32-bit integers,
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then 1000 outputs of real [0,1) numbers.
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4. The outputs
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The output of the mt19937ar.c is in the file mt19937ar.out.
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If you revise or translate the code, check the output
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by using this file.
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5. Cryptography
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This generator is not cryptoraphically secure.
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You need to use a one-way (or hash) function to obtain
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a secure random sequence.
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6. Correspondence
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See:
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URL http://www.math.keio.ac.jp/matumoto/emt.html
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email matumoto@math.keio.ac.jp, nisimura@sci.kj.yamagata-u.ac.jp
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7. Reference
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M. Matsumoto and T. Nishimura,
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"Mersenne Twister: A 623-Dimensionally Equidistributed Uniform
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Pseudo-Random Number Generator",
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ACM Transactions on Modeling and Computer Simulation,
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Vol. 8, No. 1, January 1998, pp 3--30.
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-------
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Copyright (C) 1997 - 2002, Makoto Matsumoto and Takuji Nishimura,
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All rights reserved.
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Copyright (C) 2005, Mutsuo Saito
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All rights reserved.
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