好二进制PRNG [英] Good binary PRNG
问题描述
使用rand（）和旧版本og gcc，并使用Tausworth的方法，我
在第一个数字中计算频率为0或1，如下所示：
int hist [2] = {0,0};
for（i = 0; i< 100000; ++ i）
{
++ hist [prng（）％2];
}
出于某种原因，在两种情况下，0都经常发生在1以上，无论是什么种子我用来初始化prng的种子。上面的代码中有50150 vs
49850之类的东西。
有没有人知道一个好的二进制字母。 PRNG，也就是说，在
以上的情况下会产生接近50000 vs 50000的东西？
/ David
Using rand() in and old version og gcc, and using Tausworth''s method, I
calculated the frequency of 0 or 1 in the first digit like this:
int hist[2] = {0,0};
for (i = 0; i < 100000; ++i)
{
++hist[prng() % 2];
}
For some reason, in both cases, 0 occurs more often than 1, no matter
what seed I use to initialize the prng with. Something like 50150 vs
49850 in the above code.
Does anybody know of a good "binary" PRNG, that is, one that in the
above case would make something closer to 50000 vs 50000?
/David
推荐答案
pi ****** ******@gmail.com 写道：
使用rand（）和旧版本og gcc，并使用Tausworth的方法，我
计算了第一个数字的频率为0或1，如下所示：
int hist [2] = {0,0};
for（i = 0; i< 100000 ; ++ i）
{
++ hist [prng（）％2];
}
出于某种原因，在这两种情况下，0经常发生比1，无论是什么种子我用来初始化prng。在上面的代码中有类似50150 vs
49850的内容。
有人知道一个好的二进制吗？ PRNG，也就是说，在上面的案例中会有一个接近50000 vs 50000的东西？
Using rand() in and old version og gcc, and using Tausworth''s method, I
calculated the frequency of 0 or 1 in the first digit like this:
int hist[2] = {0,0};
for (i = 0; i < 100000; ++i)
{
++hist[prng() % 2];
}
For some reason, in both cases, 0 occurs more often than 1, no matter
what seed I use to initialize the prng with. Something like 50150 vs
49850 in the above code.
Does anybody know of a good "binary" PRNG, that is, one that in the
above case would make something closer to 50000 vs 50000?
我建议你从comp.lang开始。 c如问题13.15所述的常见问题解答
我需要一个随机数发生器。您可以在
http://c-faq.com/
-
Flash Gordon，生活在有趣的时代。
网站 - http://home.flash-gordon.me.uk/
comp.lang.c发布指南和介绍：
http://clc-wiki.net/wiki / Intro_to_clc
I suggest you start with the comp.lang.c FAQ which as question 13.15 has
"I need a random number generator". You can find the FAQ at
http://c-faq.com/
--
Flash Gordon, living in interesting times.
Web site - http://home.flash-gordon.me.uk/
comp.lang.c posting guidelines and intro:
http://clc-wiki.net/wiki/Intro_to_clc
< pi ************ @ gmail.com>在消息中写道
news：11 ********************** @ i40g2000cwc.googlegr oups.com ...
<pi************@gmail.com> wrote in message
news:11**********************@i40g2000cwc.googlegr oups.com...
使用rand（）和旧版本og gcc，并使用Tausworth的方法，我在第一个数字中计算出0或1的频率，如下所示：
int hist [2] = {0,0};
for（i = 0; i< 100000; ++ i）
{
++ hist [prng（ ）％2];
}
出于某种原因，在两种情况下，0都经常发生在1以上，无论我用什么种子来初始化prng。在上面的代码中有类似50150 vs
49850的内容。
有人知道一个好的二进制吗？ PRNG，也就是说，在上面的情况下会产生接近50000和50000的东西吗？
Using rand() in and old version og gcc, and using Tausworth''s method, I
calculated the frequency of 0 or 1 in the first digit like this:
int hist[2] = {0,0};
for (i = 0; i < 100000; ++i)
{
++hist[prng() % 2];
}
For some reason, in both cases, 0 occurs more often than 1, no matter
what seed I use to initialize the prng with. Something like 50150 vs
49850 in the above code.
Does anybody know of a good "binary" PRNG, that is, one that in the
above case would make something closer to 50000 vs 50000?
很多PRNG'（Mersienne Twister，ISO C等似乎打了二进制甜蜜的
现货。在调用rand（）大约700万次之后。
使用编译器或PRNG尝试以下代码：
#include< stdio。 h>
#include< stdlib.h>
#include< time.h>
unsigned long hist [ 2] = {0,0};
int main（无效）
{
unsigned long i，value;
srand（NULL）;
for（i = 0; i< 7000000; ++ i）
{
rand（）;
}
for（i = 0; i< 100000; ++ i）
{
value = rand（）;
++ hist [value％2];
}
printf（"％ld％ld \ n"，hist [0]，hist [1]）;
return（EXIT_SUCCESS）;
}
Rod Pemberton
Many PRNG''s (Mersienne Twister, ISO C, etc.) seem to hit a binary "sweet
spot" after calling rand() about 7 million times.
Try the following code with your compiler or PRNG:
#include <stdio.h>
#include <stdlib.h>
#include <time.h>
unsigned long hist[2] = {0,0};
int main(void)
{
unsigned long i, value;
srand(NULL);
for (i = 0; i < 7000000; ++i)
{
rand();
}
for (i = 0; i < 100000; ++i)
{
value=rand();
++hist[value%2];
}
printf("%ld %ld\n",hist[0],hist[1]);
return(EXIT_SUCCESS);
}
Rod Pemberton
" Rod Pemberton" <做********* @ bitfoad.cmm>写道：
[...]
"Rod Pemberton" <do*********@bitfoad.cmm> writes:
[...]
srand（NULL）;
srand(NULL);
srand（time（NULL） ）;
-
Keith Thompson（The_Other_Keith） ks *** @ mib.org < http://www.ghoti.net/~kst>
圣地亚哥超级计算机中心< *> < http://users.sdsc.edu/~kst>
我们必须做点什么。这是事情。因此，我们必须这样做。
srand(time(NULL));
--
Keith Thompson (The_Other_Keith) ks***@mib.org <http://www.ghoti.net/~kst>
San Diego Supercomputer Center <*> <http://users.sdsc.edu/~kst>
We must do something. This is something. Therefore, we must do this.
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