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| Rev | Author | Line No. | Line |
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| 10 | reyssat | 1 | This is a Mersenne Twister pseudorandom number generator |
| 2 | with period 2^19937-1 with improved initialization scheme, |
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| 3 | modified on 2002/1/26 by Takuji Nishimura and Makoto Matsumoto. |
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| 4 | |||
| 5 | Contents of this tar ball: |
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| 6 | readme-mt.txt this file |
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| 7 | mt19937ar.c the C source (ar: initialize by ARray) |
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| 8 | mt19937ar.out Test outputs of six types generators. 1000 for each |
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| 9 | |||
| 10 | 1. Initialization |
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| 11 | The initialization scheme for the previous versions of MT |
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| 12 | (e.g. 1999/10/28 version or earlier) has a tiny problem, that |
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| 13 | the most significant bits of the seed is not well reflected |
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| 14 | to the state vector of MT. |
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| 15 | |||
| 16 | This version (2002/1/26) has two initialization schemes: |
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| 17 | init_genrand(seed) and init_by_array(init_key, key_length). |
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| 18 | |||
| 19 | init_genrand(seed) initializes the state vector by using |
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| 20 | one unsigned 32-bit integer "seed", which may be zero. |
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| 21 | |||
| 22 | init_by_array(init_key, key_length) initializes the state vector |
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| 23 | by using an array init_key[] of unsigned 32-bit integers |
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| 24 | of length key_kength. If key_length is smaller than 624, |
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| 25 | then each array of 32-bit integers gives distinct initial |
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| 26 | state vector. This is useful if you want a larger seed space |
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| 27 | than 32-bit word. |
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| 28 | |||
| 29 | 2. Generation |
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| 30 | After initialization, the following type of pseudorandom numbers |
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| 31 | are available. |
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| 32 | |||
| 33 | genrand_int32() generates unsigned 32-bit integers. |
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| 34 | genrand_int31() generates unsigned 31-bit integers. |
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| 35 | genrand_real1() generates uniform real in [0,1] (32-bit resolution). |
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| 36 | genrand_real2() generates uniform real in [0,1) (32-bit resolution). |
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| 37 | genrand_real3() generates uniform real in (0,1) (32-bit resolution). |
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| 38 | genrand_res53() generates uniform real in [0,1) with 53-bit resolution. |
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| 39 | |||
| 40 | Note: the last five functions call the first one. |
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| 41 | if you need more speed for these five functions, you may |
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| 42 | suppress the function call by copying genrand_int32() and |
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| 43 | replacing the last return(), following to these five functions. |
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| 44 | |||
| 45 | 3. main() |
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| 46 | main() is an example to initialize with an array of length 4, |
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| 47 | then 1000 outputs of unsigned 32-bit integers, |
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| 48 | then 1000 outputs of real [0,1) numbers. |
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| 49 | |||
| 50 | 4. The outputs |
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| 51 | The output of the mt19937ar.c is in the file mt19937ar.out. |
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| 52 | If you revise or translate the code, check the output |
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| 53 | by using this file. |
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| 54 | |||
| 55 | 5. Cryptography |
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| 56 | This generator is not cryptoraphically secure. |
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| 57 | You need to use a one-way (or hash) function to obtain |
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| 58 | a secure random sequence. |
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| 59 | |||
| 60 | 6. Correspondence |
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| 61 | See: |
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| 62 | URL http://www.math.keio.ac.jp/matumoto/emt.html |
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| 63 | email matumoto@math.keio.ac.jp, nisimura@sci.kj.yamagata-u.ac.jp |
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| 64 | |||
| 65 | 7. Reference |
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| 66 | M. Matsumoto and T. Nishimura, |
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| 67 | "Mersenne Twister: A 623-Dimensionally Equidistributed Uniform |
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| 68 | Pseudo-Random Number Generator", |
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| 69 | ACM Transactions on Modeling and Computer Simulation, |
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| 70 | Vol. 8, No. 1, January 1998, pp 3--30. |
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| 71 | |||
| 72 | ------- |
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| 73 | Copyright (C) 1997 - 2002, Makoto Matsumoto and Takuji Nishimura, |
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| 74 | All rights reserved. |