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Uncertain<T>

(nshipster.com)
444 points samtheprogram | 1 comments | 28 Aug 25 17:22 UTC | HN request time: 0.202s | source
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8note ◴[28 Aug 25 20:07 UTC] No.45056484[source]▶
for mechanical engineering drawings to communicate with machinists and the like, we use tolerances

eg. 10cm +8mm/-3mm

for what the acceptable range is, both bigger and smaller.

id expect something like "are we there yet" referencing GPS should understand the direction of the error and what directions of uncertainty are better or worse

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mabster ◴[28 Aug 25 22:23 UTC] No.45057720[source]▶
Something that's bugged me about this notation though is that sometimes it means "cannot exceed the bounds" and sometimes it means "only exceeds the bounds 10% of the time"
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taneq ◴[28 Aug 25 23:12 UTC] No.45058079[source]▶
I don’t think I’ve ever seen mechanical drawings have “90% confidence” dimensions like this. If a part’s too big then it won’t fit, and it’s probably useless.
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1. kevin_thibedeau ◴[28 Aug 25 23:32 UTC] No.45058208[source]▶
If a test procedure is verifying all dimensional accuracy, it can be assumed to be bounding tolerance. If it's a mass production line with less than 100% testing of parts, you'd have to expect that some outliers get by and the tolerance is something like 3-sigma on a Gaussian.