工具与资源filiph.github.io
Unsure 计算器：随手估算概率的工具
Show HN: Unsure Calculator – back-of-a-napkin probabilistic calculator
2020 — 2025，它一次次回到首页
黑点是上首页（≥ 50 分）的那次投稿，空心点是没冲上去的投稿，点越大分数越高。
导读
这是一个「餐巾纸背面」式的概率计算器：你不再输入精确数字，而是输入带不确定性的区间（默认按正态分布、上下界约 95% 置信），它用蒙特卡洛模拟算出结果的分布并画出直方图。它用极简的语法让任何人都能做粗略估算，并直观感受不确定性。
为什么经久不衰：仅新增一个「不确定数」运算符就把日常估算变成概率推理，简单到人人可用，却切中了人类不擅长直觉处理不确定性的软肋。
HN 评论精选
简单即威力，但直方图可读性、移动端/CLI 形态和源码可见性都值得改进。
我坐在这儿想，为什么这不是计算器的默认功能？太棒了。我觉得正是简单让它成功：会用计算器的人几乎都会用它，但这并不减损它的强大。人类对不确定性的直觉处理出了名地差，这个计算器或许能帮人找到感觉。唯一想改进的是直方图——那种老式控制台风格的图挺可爱，但不易读；换成现代图形并标出有用的百分位数会好很多。另外（半开玩笑地）：有 CLI/桌面/手机应用了吗？在手机上做快速心算估算很有用。还有，源码在哪？我死活找不到这个页面对应的 GitHub 仓库。
Doxin查看英文原文
And now I'm sat here wondering why this isn't a default feature on calculators. It's great! I think the simplicity really makes this work. just about anyone who can use a calculator can operate this calculator -- but that doesn't make it any less powerful. Humans are notoriously bad at intuitively dealing with uncertainty, and this calculator might very well help get a feel for it. The only thing I'd like to see improved is the histogram, the old timey console-like graphing is cute, but not exactly easy to read or interpret. Going for a modern graphical graph and marking it with some useful percentiles would go a long way towards making it more usable. EDIT: also -- only half facetiously -- is there a CLI/desktop/mobile app yet? Doing quick back-of-a-napkin math on your phone is a pretty useful thing. EDIT2: Is the source available somewhere? I'm having the hardest time finding the github repo related to this page...
追问数学原理：范围按 ±2σ 的正态分布处理，并质疑蒙特卡洛相比直接解析计算是否必要。
有人能解释一下这里的数学吗？他怎么只凭均值和范围就生成直方图？更新：我找到了——「范围始终是正态分布，下界是均值下方两个标准差，上界是上方两个标准差；就输入概率分布而言，做不到更花哨的了。」所以范围是均值 ±2 个标准差，前面某处他还提到假设输入范围是 95% 置信。如果我理解对了，第二个问题：既然有了均值和标准差，蒙特卡洛模拟到底起什么作用？不能直接细分区间、用高斯函数算频率吗？
saeranv查看英文原文
Can someone explain the math here? How is he generating the histogram from just the mean and the range? UPDATE Found this: "Range is always a normal distribution, with the lower number being two standard deviations below the mean, and the upper number two standard deviations above. Nothing fancier is possible, in terms of input probability distributions." So the range is two std dev from the mean. He also mentions somewhere early that he's assuming the input range is 95% confident. If I am understanding this correctly, I have a second question: if he has the mean, and the std dev, what is the purpose of the monte carlo simulation exactly? Can't you just subdivide your range, and compute frequency using the gaussian function?
比手动挑高低值估算更精细、更可信。
很棒。我经常靠挑一组高低数字来粗略检验假设、感受可能性的范围，这个方法更精细，也让人对答案的正确性更有信心。
Wildgoose查看英文原文
This is great. I often test assumptions by picking a set of low/high numbers to get a feel for the range of likelihood in a very crude way. This is more sophisticated and gives more confidence in the correctness of the answer.
仅靠一个新增运算符就产生巨大价值，罕见且值得收藏。
我好久没收藏过东西了，这个我收藏了。只增加一个新运算符就带来这么大的价值，令人惊叹。为这项工作感到高兴——很少有人能只加这么一点东西就做出如此独特且有价值的东西。
itodd查看英文原文
I haven't bookmarked something in ages. I bookmarked this. The value added with a single new operator is amazing. Feel good about this work. Not many people can create something so unique and valuable by adding so little.
历次讨论
同类还值得读
直接在浏览器中启动 Linux 内核
Boot a linux kernel right inside your browser.
Fabrice Bellard 的 JSLinux 页面，用 JavaScript 在浏览器里启动一个 Linux 内核，并提供一个可交互的终端环境。
工具与资源上首页 5 次 · 2011–2025bellard.orgHacker News 未公开功能与行为清单（2018）
A List of Hacker News's Undocumented Features and Behaviors (2018)
数据科学家 Max Woolf 整理的 Hacker News 未公开功能与行为清单，涵盖投票机制、排名算法、账号惩罚等社区运作细节。
工具与资源上首页 5 次 · 2019–2025github.comMapSCII：在终端中用盲文和 ASCII 渲染地图
MapSCII – Braille and ASCII map renderer for the console
MapSCII 是一个在命令行终端里渲染地图的开源工具，用盲文字符和 ASCII 字符把地理数据画成可交互浏览的字符地图。
工具与资源上首页 5 次 · 2017–2025github.com顶尖大学的免费在线课程
Free Online Courses from Top Universities
Open Culture 整理的一份免费在线课程合集，汇集了全球顶尖大学（如 MIT、斯坦福、耶鲁等）向公众开放的网络课程资源，涵盖音频、视频等多种形式。
工具与资源上首页 5 次 · 2010–2022openculture.com淘气字符串：容易引发用户输入问题的字符串清单
Naughty Strings: A list of strings likely to cause issues as user-input data
一个 GitHub 仓库，收录了大量容易让程序出问题的用户输入字符串，如特殊字符、emoji、SQL 注入片段、系统命令等，供开发者用于测试输入处理逻辑。
工具与资源上首页 4 次 · 2015–2020github.com