What Is a Nomogram and Why Would It Interest Me? | Hacker News Reader

What Is a Nomogram and Why Would It Interest Me?

lefakkomies.github.io

152 pointsEridanus224 comments

Seriously, though, there's one nomogram you (yes you) should know about and have it well-enough engraved in your mind's eye that you can use it with eyes closed. A nomogram for Bayes' theorem: https://www.ovid.com/journals/nejm/abstract/10.1056/nejm1975...

That was a bit small on my screen. Found an interactive one here that's scalable - https://www.medcalc.org/en/calc/fagans-nomogram.php

That is cool, although it took me awhile to understand it because the posterior probability is on the left and the prior probability is on the right, and because it uses D=Disease and T=Test when I am used to seeing D=Data.

Neat. This is based on Bayes' rule in its odds form[1], or more specifically in log-odds form, where evidence is additive[2].

[1]: https://entropicthoughts.com/bayes-rule-odds-form

[2]: https://entropicthoughts.com/sensitivity-counts-against-you

Actually I find nomograms in log form really cool for making naive bayes classifiers 'explainable'. One can even add density for continuous values.

IMHO this is so much nicer than e.g. decisions tree visualizations (which everyone quotes for the most explainable AI models).

It is indeed a great tool for visualizing Bayesian relations. You can even "feel" the sensitivity.

Can you use actually use it eyes closed? Never heard of that level of precision in the mind's eye

You're right that I can't reproduce it like a phone camera could, and that the more precise you are the better (and it might be that with my eyes closed I'm doing something closer to addition in log-odds, like a separate comment responded), but this is super useful even coarsely. The visual affordance gives Bayes's theorem a physicality unlike any other tool I've found.

If you like things like this I can recommend you check out the Chris Staecker youtube channel. He covers all sorts of tools people used to use to do math before computers and calculators, and there are a lot of them. Some of the things people came up with to do what today would be considered relatively simple math are pretty clever, pretty complex, or both.

https://www.youtube.com/@ChrisStaecker

The Smith chart is the electrical engineer's favorite: https://en.wikipedia.org/wiki/Smith_chart

You either love it or hate it, depending on how well your electromagnetics class was taught.

Here’s an old python program to make pdf nomograms from almost any formula. The example of payment for a loan is one of my favorites.

https://github.com/lefakkomies/pynomo

That is TFA.

Somehow I looked at the article and completely missed that it was the introduction to Pynomo. My wife would back you up that I am not good at finding things...

MTU Network Tunneling.

Router-protocol specification.

There's an old paper about the mathematics of nomograms that I found interested when I stumbled across it: https://doi.org/10.1016/0001-8708(65)90042-3

I am fascinated with nomograms ever since I stumbled upon them.

I spent some time earlier this year creating one for two resistors in parallel. I had seen it in an old book [1] but it was of poor quality.

(I tried to get Gemini writing to write code to generate an SVG file—but it was pretty poor compared to the one that I had done by hand in Affinity Designer.)

[1] https://www.worldradiohistory.com/BOOKSHELF-ARH/Technology/T...

I read the title as "Nonogram" (Picross) at first !

I read PyNomo as "Py no mo' " and was overcome by a feeling of loss.

video explaining what a Nomogram is and how to make them by hand https://www.youtube.com/watch?v=GCd9hANNLsw

The US Navy still uses nomograms for chemistry control on nuclear reactors!

Also those who want to quit doing drugs should have one.

So far my children have not yet had to repeatedly perform complicated calculations, but I look forward to the day. I will definitely teach them with nomograms before we go on to spreadsheets!

Another type of almost-nomogram that's great and practical is the slide rule. In particular in the kitchen, where it makes it really easy to translate proportions. https://entropicthoughts.com/kitchen-slide-rule

I think the Numogram is more interesting, highly relevant today due to AI happenings

Reply on news.ycombinator.com