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cyrand 产生的随机数不均匀

Open Henry-ZHR opened this issue 3 years ago • 8 comments

如题

还有,标准库都有的东西为啥要重复造轮子

Henry-ZHR avatar Aug 08 '20 02:08 Henry-ZHR

您是指cyrand还是cyrand_ll? cyrand循环节更大

------------------ 原始邮件 ------------------ 发件人: "optimize-2/Crayon" <[email protected]>; 发送时间: 2020年8月8日(星期六) 上午10:26 收件人: "optimize-2/Crayon"<[email protected]>; 抄送: "Subscribed"<[email protected]>; 主题: [optimize-2/Crayon] cyrand 产生的随机数不均匀 (#3)

如题

还有,标准库都有的东西为啥要重复造轮子

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optimize-2 avatar Aug 08 '20 03:08 optimize-2

都是

不是循环节

得到的数概率不一样

Henry-ZHR avatar Aug 08 '20 03:08 Henry-ZHR

怎么得出这个结论的/yiw

------------------ 原始邮件 ------------------ 发件人: "optimize-2/Crayon" <[email protected]>; 发送时间: 2020年8月8日(星期六) 中午11:58 收件人: "optimize-2/Crayon"<[email protected]>; 抄送: "optimize_谔"<[email protected]>;"Comment"<[email protected]>; 主题: Re: [optimize-2/Crayon] cyrand 产生的随机数不均匀 (#3)

都是

不是循环节

得到的数概率不一样

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optimize-2 avatar Aug 08 '20 03:08 optimize-2

建议参考 std::uniform_int_distribution 的实现

Henry-ZHR avatar Aug 08 '20 03:08 Henry-ZHR

ok

------------------ 原始邮件 ------------------ 发件人: "optimize-2/Crayon" <[email protected]>; 发送时间: 2020年8月8日(星期六) 中午11:59 收件人: "optimize-2/Crayon"<[email protected]>; 抄送: "optimize_谔"<[email protected]>;"Comment"<[email protected]>; 主题: Re: [optimize-2/Crayon] cyrand 产生的随机数不均匀 (#3)

建议参考 std::uniform_int_distribution 的实现

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optimize-2 avatar Aug 08 '20 04:08 optimize-2

怎么得出这个结论的/yiw ------------------ 原始邮件 ------------------ 发件人: "optimize-2/Crayon" <[email protected]>; 发送时间: 2020年8月8日(星期六) 中午11:58 收件人: "optimize-2/Crayon"<[email protected]>; 抄送: "optimize_谔"<[email protected]>;"Comment"<[email protected]>; 主题: Re: [optimize-2/Crayon] cyrand 产生的随机数不均匀 (#3) 都是 不是循环节 得到的数概率不一样 — You are receiving this because you commented. Reply to this email directly, view it on GitHub, or unsubscribe.

假设 MTrand 等概率产生 1 到 3 的整数,然后你模一个 2,这样的话得到的 1 的概率是 2/3,得到 0 的概率是 1/3,概率就会不一样

当然,你本身范围比这个大很多,这个不会很明显地体现出来,但如果想给别人用的话还是建议注意一下

Henry-ZHR avatar Aug 08 '20 04:08 Henry-ZHR

(你这项目貌似小毛病挺多,我只是刚好看到这个就过来发了

Henry-ZHR avatar Aug 08 '20 04:08 Henry-ZHR

哦 thks

------------------ 原始邮件 ------------------ 发件人: "optimize-2/Crayon" <[email protected]>; 发送时间: 2020年8月8日(星期六) 中午12:05 收件人: "optimize-2/Crayon"<[email protected]>; 抄送: "optimize_谔"<[email protected]>;"Comment"<[email protected]>; 主题: Re: [optimize-2/Crayon] cyrand 产生的随机数不均匀 (#3)

(你这项目貌似小毛病挺多,我只是刚好看到这个就过来发了

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optimize-2 avatar Aug 08 '20 04:08 optimize-2