Very cool. This can also be used for LLM cost estimation. Basically any cost estimation I suppose. I use cloudflare workers a lot and have a few workers running for a variable amount of time. This could be useful to calculate a ball park figure of my infra cost. Thank you!
Show HN: Unsure Calculator – back-of-a-napkin probabilistic calculator
81–90 of 170 posts
Re: Show HN: Unsure Calculator – back-of-a-napkin probabilistic calculator
#82This is awesome. I used Causal years ago to do something similar, with perhaps slightly more complex modelling, and it was great. Unfortunately the product was targeted at high paying enterprise customers and seems to have pivoted into finance now, I've been looking for something similar ever since. This probably solves at least, err... 40~60% of my needs ;)
Re: Show HN: Unsure Calculator – back-of-a-napkin probabilistic calculator
#83I have written similar tools - for command line, fermi: https://git.nunosempere.com/NunoSempere/fermi - for android, a distribution calculator: https://f-droid.org/en/packages/com.nunosempere.distribution... People might also be interested in https://www.squiggle-language.com/ , which is a more complex version (or possibly https://git.nunosempere.com/personal/squiggle.c >, which is a faster but much more verbose vers…
Fermi in particular has the following syntax ``` 5M 12M # number of people living in Chicago beta 1 200 # fraction of people that have a piano 30 180 # minutes it takes to tune a piano, including travel time / 48 52 # weeks a year that piano tuners work for / 5 6 # days a week in which piano tuners work / 6 8 # hours a day in which piano tuners work / 60 # minutes to an hour ``` multiplication is implied as the defau…
Oh, this is very similar to what I have with Precel, less syntax. Thanks for sharing!
Re: Show HN: Unsure Calculator – back-of-a-napkin probabilistic calculator
#84Chalk also supports uncertainty : https://chachatelier.fr/chalk/chalk-features.php (combined with arbitrary long numbers and interval arithmetic)
Re: Show HN: Unsure Calculator – back-of-a-napkin probabilistic calculator
#85Re: Show HN: Unsure Calculator – back-of-a-napkin probabilistic calculator
#86Earlier quoted context omitted.
This jives with my general reaction to the post, which was that the added complexity and difficulty of reasoning about the ranges actually made me feel less confident in the result of their example calculation. I liked the $50 result, you can tack on a plus or minus range but generally feel like you're about breakeven. On the other hand, "95% sure the real balance will fall into the -$60 to +$220 range" feels like it…
It is producing a useful number. As more truly independent terms are added, error grows with the square root while the point estimation grows linearly. In the aggregate, the error makes up less of the point estimation. This is the reason Fermi estimation works. You can test people on it, and almost universally they get more accurate with this method. If you got less certain of the result in the example, that's probab…
> People are default overconfident with their estimated error bars.
You say this but yet roughly in a top level comment mentions people keep their error bars too close.
Re: Show HN: Unsure Calculator – back-of-a-napkin probabilistic calculator
#87This is super cool.
It seems to break for ranges including 0 though
100 / -1~1 = -3550~3500
I think the most correct answer here is -inf~inf
Re: Show HN: Unsure Calculator – back-of-a-napkin probabilistic calculator
#88The ASCII art (well technically ANSI art) histogram is neat. Cool hack to get something done quickly. I'd have spent 5x the time trying various chart libraries and giving up.
Here [1] is a nice implementation written in Awk. A bit rough around the edges, but could be easily extended.
Re: Show HN: Unsure Calculator – back-of-a-napkin probabilistic calculator
#89Feature request: allow specifying the probability distribution. E.g.: ‘~’: normal, ‘_’: uniform, etc.
Not having this feature is a feature—they mention this.
Not really, or at least not permanently; uniform distribution is mentioned in a github changelog, perhaps it’s an upcoming feature:
> 0.4.0
> BRAKING: x~y (read: range from x to y) now means "flat distribution from x to y". Every value between x and y is as likely to be emitted.
> For normal distribution, you can now use x+-d, which puts the mean at x, and the 95% (2 sigma) bounds at distance d from x.
https://github.com/filiph/unsure/blob/master/CHANGELOG.md#04...
Re: Show HN: Unsure Calculator – back-of-a-napkin probabilistic calculator
#90Earlier quoted context omitted.
From link: > Heaviest blue whale ever recorded I don't think estimation errors regarding things outside of someone's area of familiarity say much. You could ask a much "easier"" question from the same topic area and still get terrible answers: "What percentage of blue whales are blue?" Or just "Are blue whales blue?" Estimating something often encountered but uncounted seems like a better test. Like how many cars pas…
I have no familiarity with blue whales but I would guess they're 1--5 times the mass of lorries, which I guess weigh like 10--20 cars which I in turn estimate at 1.2--2 tonnes, so primitively 12--200 tonnes for a normal blue whale. This also aligns with it being at least twice as large as an elephant, something I estimate at 5 tonnes. The question asks for the heaviest, which I think cannot be more than three times t…
I would say general knowledge in many domains may help with this as you can try and approximate to the nearest thing you know from that domain.
How you get good at being a generalist is the tricky part, my best bet is reading and doing a lot of trivia (I found crosswords to be somewhat effective at this, but far from being efficient)