6 ms·
This is not a very good list. Several items are between "misleading" and "wrong": 1. "Pipe" should be called "bar" (IMO) 2. "Vector norm" is a much deeper ide
by exmadscientist 7y ago
This is not a very good list. Several items are between "misleading" and "wrong":
1. "Pipe" should be called "bar" (IMO)
2. "Vector norm" is a much deeper idea than just "2-norm" and if you limit yourself to the 2-norm, you will run into problems
3. "Set membership" is not called "epsilon"!
4. I wouldn't describe functions as operating on "pools", but that's just me. ("Pools" seems to imply vector arguments, or at least set arguments, which is not how functions are usually thought of operating, though they are defined that way.)
5. The description of R^2 as "2-D array" is wrong.
6. I've never seen that notation for elementwise multiplication, though that doesn't mean much.
7. I've rarely seen that notation for dot products. Usually the center dot is much more common.
8. Hat is... nonstandard. It has many, many meanings.
- justinmeiners 7y agoGood points. I know you know, but it's also worth mentioning that most math symbols don't have a definite meaning. Meaning is defined in the context it is presented, in whatever way the author feels makes the most sense. Math is a natural, not a formal language.
- WilliamEdward 7y agoIs that really true though? having precise definitions for symbols is important for proofs
- throwaway_pdp09 7y agoYes, it's true. Please re-read what he said, especially the "in the context of" part.
- reikonomusha 7y agoIn "proper" mathematics, the symbols are defined precisely in their context. This does not mean that the symbols' meanings are universal. I think this is what GP meant. The lack of universality of meanings of symbols is a feature, not a bug, of math notation.
- carapace 7y agoThe messed up thing is that the math notation of computer science is in the same mess. It doesn't even have a name. (There's a talk about it but I can't find the link right now.)
- carapace 7y agoFound it! "It's Time for a New Old Language" – Guy Steele [video] (youtube.com) https://news.ycombinator.com/item?id=15473199 https://news.ycombinator.com/item?id=15473199 https://www.youtube.com/watch?v=dCuZkaaou0Q https://www.youtube.com/watch?v=dCuZkaaou0Q
- justinmeiners 7y agoThis isn't a mess, this is a good thing. Math is a way of talking about ideas, not a formal system for computers.
- carapace 7y agoSo what's the difference in your view between math and philosophy?
- justinmeiners 7y agoThat's a little complicated as math is intertwined with science. But at the core I only see them as a difference in subject matter. Math is a philosophical study of space, logical structure, quantity, etc. Proofs are just tools for articulating arguments about these subjects. Deduction just tends to work better in math, so the methods are more refined and agreed upon.
- m463 7y agoI took a philosophy course in college to learn symbolic logic
- seemslegit 7y agoAll this plus - explaining "element wise multiplication" by referring to np.multiply is not very explanatory.
- reikonomusha 7y agoIn the old days of typesetting, folks actually did use an epsilon for \in! Of course, these days with LaTeX, it would be very odd to see that.
- kmill 7y agoThe set membership symbol is called a lunate epsilon. As I half remember, someone used the Greek version of the first letter of the Latin word "est," meaning "is."