4 ms·

Sorry, I'm too busy trying to check an algorithm to convert floating-point numbers to strings for correctness to deal with people playing the "I'm a rocket scie

Sorry, I'm too busy trying to check an algorithm to convert floating-point numbers to strings for correctness to deal with people playing the "I'm a rocket scientist, therefore everything is easy to me" card. And yet somehow Elon isn't that (see his most recent SpaceX, where he quite literally uses that to justify his competence to build orbital data centers).

hparadiz 2mo ago
[flagged]
- jcranmer 2mo ago
  Thank you for putting words into my mouth that I didn't say. Especially when they're quite literally the opposite of my message. Although, given that I pointed out that Elon literally did the exact same thing, why do you trust him when he does it? Or is it simply that you're unaware that he does stuff like that?
  - WalterBright 2mo ago
    > why do you trust him when he does it? His companies have made many monumental engineering achievements at his direction.
    - jcranmer 2mo ago
      His companies making those achievements is not the same as he personally making those achievements. He does have some talent in being a CEO of a company and inspiring employees and investors. But also don't oversell that: only Tesla and SpaceX have been successes, and he's had to have them bail out is other failed companies: SolarCity, Twitter, and xAI. The Boring Company also doesn't seem to be particularly successful either, and he never got around to building a company to build Hyperloop in the first place.
      - WalterBright 2mo ago
        The Boring Company is profitable. > His companies making those achievements is not the same as he personally making those achievements. Those achievements wouldn't have happened without him. > He does have some talent in being a CEO of a company and inspiring employees and investors. SpaceX employees are top shelf engineers and scientists. Being able to do that makes Musk a great CEO. Can you name any other CEO who has been able to do anything like what Musk's companies do?
        watutalkinbout 2mo ago
        Steve jobs was not a great engineer. He was ruthless, manipulative and lacking empathy - like Musk.
        WalterBright 2mo ago
        And Apple never would have existed without Jobs. Apple was 90 days from bankruptcy when the Second Coming of Jobs occurred. He took the same company, with the same engineers, from near bankruptcy to $347 billion. Again, same engineers. 90 days from bankruptcy to $347 billion. Jobs was the magic ingredient - like Musk.
        watutalkinbout 2mo ago
        And he wasn't an engineer.
    - jedberg 2mo ago
      > His companies have made many monumental engineering achievements at his direction. If you know anyone who has worked at one his companies, especially at a high level, you would know that they made those achievements despite his directions. The SpaceX team was ecstatic when he bought Twitter, because it meant he would be around a lot less. The policy at SpaceX was basically avoid Elon, and if you had to talk to him, just agree to whatever he said and then not do it. He almost always forgot by the next time he talked to you, and if he didn't, you just said it was really hard. Since he doesn't understand rocket engineering, it was pretty easy to get away with that. And the people who worked with him at PayPal would tell you that he knows nothing about software engineering and they basically threw away everything he wrote, but they had to be nice because he had a lot of stock after his company was acquired by PayPal but called a merger. Elon's main skill is marketing himself. He next best skill is marketing his companies' jobs to talented people and getting them to agree to work there. That is certainly a critical skill for a CEO, but he is not a great engineer.
      - hparadiz 2mo ago
        [flagged]
        watutalkinbout 2mo ago
        Dat u Elon?
        hparadiz 1mo ago
        You know I'm posting with my real name right?
WalterBright 2mo ago
I implemented float-to-string for my compiler's printf back sometime before 1985. It's a medium difficult problem. Once you understand engineering, transferring that skill to another engineering discipline is not that hard. For example, the equations for Newtonian mechanics, electronics, beam design, rotating inertia, etc., are interchangeable. > his competence to build orbital data centers Since nobody has yet built an orbital data center, nobody is competent at it yet.
- nrr 2mo ago
  > I implemented float-to-string for my compiler's printf back sometime before 1985. It's a medium difficult problem. It might have been medium difficult back in 1985, but the state of the art has progressed in the intervening 40 years. The constraint of correctness makes things trickier because it further imposes three requirements: completeness, uniqueness, and determinism. Unless the implementer has the skill to prove these properties about the algorithm they've implemented, such an implementation is likely not to achieve those requirements.
  - WalterBright 2mo ago
    There was no test suite for it available that I could use for correctness checks, so I did what I could. I also implemented IEEE 754 floating point in asm. For that I did have an exhaustive test suite, and passed it 100%.
    - nrr 2mo ago
      We didn't have this definition of correctness until 1990 (due to Steele and White), and it wasn't until the past decade or so that we got a published algorithm (most recently, I think, Dragonbox, due to Jeon when he was still working on his PhD at UCSD), with mathematical proof[0], that satisfied all of the requirements of being complete, being unique, and being deterministic. (Though, Steele-White expresses these slightly differently, as preserving information, having the shortest possible output, and rounding correctly. Completeness, uniqueness, and determinism seem to be equivalent and are easier to prove.) -- 0: Available at <https://fmt.dev/papers/Dragonbox.pdf https://fmt.dev/papers/Dragonbox.pdf>. It's pretty easy to understand either with a numerical analysis background or after having worked through volume 2 of Knuth's TAoCP.

hparadiz 2mo ago

[flagged]

jcranmer 2mo ago
Thank you for putting words into my mouth that I didn't say. Especially when they're quite literally the opposite of my message. Although, given that I pointed out that Elon literally did the exact same thing, why do you trust him when he does it? Or is it simply that you're unaware that he does stuff like that?
- WalterBright 2mo ago
  > why do you trust him when he does it? His companies have made many monumental engineering achievements at his direction.
  - jcranmer 2mo ago
    His companies making those achievements is not the same as he personally making those achievements. He does have some talent in being a CEO of a company and inspiring employees and investors. But also don't oversell that: only Tesla and SpaceX have been successes, and he's had to have them bail out is other failed companies: SolarCity, Twitter, and xAI. The Boring Company also doesn't seem to be particularly successful either, and he never got around to building a company to build Hyperloop in the first place.
    - WalterBright 2mo ago
      The Boring Company is profitable. > His companies making those achievements is not the same as he personally making those achievements. Those achievements wouldn't have happened without him. > He does have some talent in being a CEO of a company and inspiring employees and investors. SpaceX employees are top shelf engineers and scientists. Being able to do that makes Musk a great CEO. Can you name any other CEO who has been able to do anything like what Musk's companies do?
      - watutalkinbout 2mo ago
        Steve jobs was not a great engineer. He was ruthless, manipulative and lacking empathy - like Musk.
        WalterBright 2mo ago
        And Apple never would have existed without Jobs. Apple was 90 days from bankruptcy when the Second Coming of Jobs occurred. He took the same company, with the same engineers, from near bankruptcy to $347 billion. Again, same engineers. 90 days from bankruptcy to $347 billion. Jobs was the magic ingredient - like Musk.
        watutalkinbout 2mo ago
        And he wasn't an engineer.
  - jedberg 2mo ago
    > His companies have made many monumental engineering achievements at his direction. If you know anyone who has worked at one his companies, especially at a high level, you would know that they made those achievements despite his directions. The SpaceX team was ecstatic when he bought Twitter, because it meant he would be around a lot less. The policy at SpaceX was basically avoid Elon, and if you had to talk to him, just agree to whatever he said and then not do it. He almost always forgot by the next time he talked to you, and if he didn't, you just said it was really hard. Since he doesn't understand rocket engineering, it was pretty easy to get away with that. And the people who worked with him at PayPal would tell you that he knows nothing about software engineering and they basically threw away everything he wrote, but they had to be nice because he had a lot of stock after his company was acquired by PayPal but called a merger. Elon's main skill is marketing himself. He next best skill is marketing his companies' jobs to talented people and getting them to agree to work there. That is certainly a critical skill for a CEO, but he is not a great engineer.
    - hparadiz 2mo ago
      [flagged]
      - watutalkinbout 2mo ago
        Dat u Elon?
        hparadiz 1mo ago
        You know I'm posting with my real name right?

WalterBright 2mo ago

I implemented float-to-string for my compiler's printf back sometime before 1985. It's a medium difficult problem. Once you understand engineering, transferring that skill to another engineering discipline is not that hard. For example, the equations for Newtonian mechanics, electronics, beam design, rotating inertia, etc., are interchangeable. > his competence to build orbital data centers Since nobody has yet built an orbital data center, nobody is competent at it yet.

nrr 2mo ago
> I implemented float-to-string for my compiler's printf back sometime before 1985. It's a medium difficult problem. It might have been medium difficult back in 1985, but the state of the art has progressed in the intervening 40 years. The constraint of correctness makes things trickier because it further imposes three requirements: completeness, uniqueness, and determinism. Unless the implementer has the skill to prove these properties about the algorithm they've implemented, such an implementation is likely not to achieve those requirements.
- WalterBright 2mo ago
  There was no test suite for it available that I could use for correctness checks, so I did what I could. I also implemented IEEE 754 floating point in asm. For that I did have an exhaustive test suite, and passed it 100%.
  - nrr 2mo ago
    We didn't have this definition of correctness until 1990 (due to Steele and White), and it wasn't until the past decade or so that we got a published algorithm (most recently, I think, Dragonbox, due to Jeon when he was still working on his PhD at UCSD), with mathematical proof[0], that satisfied all of the requirements of being complete, being unique, and being deterministic. (Though, Steele-White expresses these slightly differently, as preserving information, having the shortest possible output, and rounding correctly. Completeness, uniqueness, and determinism seem to be equivalent and are easier to prove.) -- 0: Available at <https://fmt.dev/papers/Dragonbox.pdf https://fmt.dev/papers/Dragonbox.pdf>. It's pretty easy to understand either with a numerical analysis background or after having worked through volume 2 of Knuth's TAoCP.