• I_Has_A_Hat@lemmy.world
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    2 days ago

    Never, in any engineering field, have I EVER seen anyone simplify pi to 5. For that matter, I have never seen anyone simplify to 3. It is always 3.14. I feel like pi simplification is a weird meme that people think engineers do but is never practiced anywhere.

    It’s like if there was a meme about chefs saying they always replace eggs with grapefruit. No they don’t, and it’s nonsense to think they do.

    • mrgoosmoos@lemmy.ca
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      2 days ago

      you’ve never seen anybody simplify it to 3 when doing head calcs without a phone nearby?

      it doesn’t happen often, in fact I’ve seen it once. in a decade.

      • I_Has_A_Hat@lemmy.world
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        2 days ago

        The only time you should be doing head calcs as an engineer is to double check that you have a reasonable answer with the actual calcs on your actual calculator.

    • qjkxbmwvz@startrek.website
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      2 days ago

      For back-of-the-envelope or mental calculations, pi is often 3 or 10^(1/2).

      The latter is better than 1% accurate, and has nice properties when doing order-of-magnitude/log space calculations in base 10.

    • Kaboom@reddthat.com
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      2 days ago

      There’s a lot of weird stereotypes out there that make no sense. Like the whole “programmers wear thigh high socks” thing. Where did that even come from?

    • bus_factor@lemmy.world
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      2 days ago

      There’s less and less reason to do it (and it’s never 5). On systems without floating point you might want to do round it a bit, but only if the specific thing you’re doing allows it, and even then you’re more likely to do a fixed-point approach by using e.g. 314 and dividing by 100 later, or adjusting that value a bit so you can divide by 128 via bitshift if you’re on a chip where division is expensive. However, in 2025 you almost certainly should have picked a chip with an FPU if you’re doing trigonometry.

      And while rounding pi to 3 or 4 is certainly just a meme, there are other approximations which are used, like small-angle approximations, where things like sin(x) can be simplified to just x for a sufficiently small x.