creata

58 ms·

871.
by creata 6y ago
Yeah, it is a rare problem, but it's not that rare when writing anything generic. For example, look at all the special-casing of null (ctrl-f "null") in the Java HashMap docs.[0] All of that would immediately go away if t
872.
by creata 6y ago
> It's not the only sensible definition Right, which is why I said it's just one sensible definition. :) Although I guess there's at least two sensible definitions of arithmetic on List<int>, too.
873.
by creata 6y ago
They're not the same, and the biggest difference is explained in the Map<int, Option<String>> example: union types merge different uses of null that you usually don't want merged.
874.
by creata 6y ago
> You need union types if you have subtyping to avoid wrapping/unwrapping all the time. In my experience, the option types are always more concise. That's mostly because having option types encourages people to build out nice h
875.
by creata 6y ago
I agree that union-typed null was the best solution for Dart, but I think many of the article's criticisms of option types aren't good. > We can’t perform arithmetic on an Option<int> any more than we could on a List<i
876.
by creata 6y ago
Maybe you've just a bad math department? None of my math lecturers ever just "wrote things on the board". > He said "a derivative of a function is the rate of change of that function." I'm confused by this c
877.
by creata 6y ago
> SymPy is pretty niche I don't know; I use isympy (interactive sympy, uses IPython if installed) as a local Wolfram Alpha for all my math problems, and it's really good at that.
878.
by creata 6y ago
Here's yet another page with some code examples: https://www.jeremyong.com/klein/geometry-potpourri/
879.
by creata 6y ago
Not with just a rotor (quaternion) and an offset, or with motors (dual quaternions). If you want nonuniform scaling, rotation and translation, then matrices are probably the nicest way to do that.
880.
by creata 6y ago
I'm not sure what you mean. Let Ax mean rotating x by A (which is a rotation matrix, quaternion, rotor, whatever). Then, the composition of Ax + b and Cx + d is C(Ax + b) + d = (CA)x + (Cb + d).
881.
by creata 6y ago
Like enkimute said, your options re translation are exactly the same with matrices and with geometric algebra: either carry a vector offset with you, or move to projective space (homogeneous coordinates).
882.
by creata 6y ago
Look, you already need a bilinear form to get the Hodge star. My point is that with that same bilinear form you also get an entire Clifford algebra, and a much more natural definition of the Hodge star. That's all I'm saying. Is t
883.
by creata 6y ago
If I remember correctly, the Hodge star much more closely belongs to geometric algebras than it does to exterior algebras, since you need a nondegenerate bilinear form to define the Hodge star, from which you can just as easily define the g
884.
by creata 6y ago
> probably with less bugs than the standard one… We're not talking about the implementation, but the design. That's not how most people use the word "bug".
885.
by creata 6y ago
It's worse. Even if you do know how regexes work, you can still be tripped up by the counterintuitive function names. See this comment[0] and its parent for an example. I think English names with ambiguous or unexpected meanings are
886.
by creata 6y ago
The New York Times is one of the most respected news organizations in the world, so if they're not a "professional news org", then who is? Also, do you elaborate on your struggle with the NYT elsewhere? I'm interested, b
887.
by creata 6y ago
Honestly, I think it's part of the solution. Too many words are spent in online arguments between two people who aren't at all open to changing their beliefs. If people are willing to admit that at the outset, everyone's ti
888.
by creata 6y ago
As Quekid5 said, isn't that the way things should be? Adding tracing is a breaking change, and adding logging inside a deeply nested layer is a breaking change to all the outer layers, too.
889.
by creata 6y ago
It's primarily useful for theorem proving, where a nonterminating argument corresponds to circular or otherwise unfounded reasoning. It's also useful because, in practice, we don't accidentally write code that "obviously
890.
by creata 6y ago
Do you have any introductory material on cubical type theory, suitable for the average mathematician? The type theory in Lean feels dead simple to me, but all the online resources on cubical type theory feel impenetrable.
891.
by creata 6y ago
Jabberwocky is a poem by Lewis Carroll. https://en.wikipedia.org/wiki/Jabberwocky
892.
by creata 6y ago
I don't know what Vale's "USP" is, and I think you're right to point out that it doesn't really sell itself on its front page. But you're being a massive dick about the marketing of a language which is c
893.
by creata 6y ago
Yep. Even when you're doing something as simple as iterating over some data structure, you have to remember not to mutate it. Rust enforces that, but Python just either corrupts the data structure / iterator, or if you're lu
894.
by creata 6y ago
> non-metrical contexts How do you get a geometric algebra without at least a pseudo-Riemannian metric?
895.
by creata 6y ago
Minor correction: the inclusion of the vectors is (a, b) ⇒ (0, a, b, 0), not (1, a, b, 0). Also, you have an inclusion of the scalars, which is x ⇒ (x, 0, 0, 0). And yeah, G^2 can't be projected back onto R^2 without losing a lot of in
896.
by creata 6y ago
> When people talk about it, it always sounds like a simple generalization of exterior algebra. And so it is. Sure, both are quotients of tensor algebras, but if anything, it's the other way around. Geometric algebra is to exterior
897.
by creata 6y ago
* The space of multivectors in Rⁿ is actually also a vector space, and it's 2ⁿ-dimensional. The standard basis of this vector space (in 2 dimensions) is {1, x, y, x ∧ y = xy}, and that's why we care about representing uv in term
898.
by creata 6y ago
Yep. For a silly analogy, it's like saying that set theory will replace every field of mathematics.
899.
by creata 6y ago
Do you have some before-and-after code that you can share? I've seen two other efforts in that general direction: * "Let's Remove Quaternions from Every 3D Engine"[0], which was underwhelming: let's ask other people
900.
by creata 6y ago
> Few projects ascend to the astral planes of immortality. If even Xorg doesn't qualify, which are these few immortal projects?

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