joppy

7 ms·

31.
by joppy 4y ago
Yeah I have never seen anything like that in NSW either - anyway on 38°+ days one would have to spray continually anyway, and there’s no way you could do that along a whole rail line in a country that routinely experiences droughts and wate
32.
by joppy 4y ago
To get something useful and not attackable, the complement operation would need to take the complement inside the set of valid UTF-8 strings rather than the set of all byte-sequences, which is probably doable but I'm not sure how strai
33.
by joppy 4y ago
T.Tao's first publication (at least the first one that shows up on MathSciNet) was in 1996, the same year he finished his mathematics PhD. I would say for most people working towards the pure side of mathematics, having over 5 papers b
34.
by joppy 4y ago
I would recommend looking not only at books, but at online video lecture recordings (from reputable sources). There is so much intuition you get from someone actually discussing and problem-solving in front of you, not to mention (especiall
35.
by joppy 4y ago
To be clear, it was a very low-traffic (both car and foot) location - neither would expect to encounter each other almost ever. I thought the decision to not encourage pedestrians into a false sense of security was a sensible one.
36.
by joppy 4y ago
I applied to my local council (in Australia) for a pedestrian crossing to be painted somewhere near my home where a footpath from a park comes out onto the road, and pedestrians need to cross to the other side of the road. Seemed like a rea
37.
by joppy 4y ago
For pages with lots of mathematics markup, it is far better (in terms of download size) to send the latex markup and the katex library to the browser, and render it there. I tried rendering the mathematics server-side using katex on my own
38.
by joppy 4y ago
This decomposition is not used much because it is not unique in any sense, it is not numerically stable, and it is fairly uninteresting: the matrix D can always be taken to consist of a diagonal of 1s of length rank(A) and the rest zeros. I
39.
by joppy 4y ago
Are you sure this is not just the amount of exposure to each type of clock? On the other hand, I’ve noticed that children who understand how to read only digital clocks are quite capable of answering what the time is (just read the numbers
40.
by joppy 4y ago
Right, but I would probably test the output while compressing instead of putting a big USE AT YOUR OWN PERIL sign across the front…
41.
by joppy 4y ago
Why is there such a big disclaimer/warning on the front? Shouldn’t the program just check that decompress(compress(x)) = x as it goes, and then it can be sure that compress(x) has not lost any data?
42.
by joppy 4y ago
Companies do this all the time with share-based compensation don’t they?
43.
by joppy 5y ago
Because of how floating-point numbers are distributed, you should expect a random number drawn uniformly from [0,1] to basically never hit the smallest floating-point number: hitting something in the range [0, 2^-n] should happen with proba
44.
by joppy 5y ago
I’m also on 15.3.1. The huge “Up Next” menu (the first thing on the first page) is what I’m describing - perhaps you need to subscribe to some podcasts before you see it. Clicking the purple durations next to the play button always starts t
45.
by joppy 5y ago
What do you think of the iOS podcasts app then? I have no idea of where to press to view details of a podcast, vs to start playing it. On the main page, the black text starts playing a podcast, and the purple text shows details. Further int
46.
by joppy 5y ago
Wikipedia is a terrible place to learn advanced mathematics, for the reasons you raise (and more). There are lots of terrific short books, and many terrific lectures online.
47.
by joppy 5y ago
In MAGMA, a computer algebra programming language, there is a “exists” statement which takes a comprehension and evaluates to true if any item is true, something like exists{x % 2 == 0 for x in numbers}. But it also has an extra parameter w
48.
by joppy 5y ago
I guess the author has never done any (two extremely specific subfields) work? Most people don’t need to convert characters into numbers, there’s nothing overly surprising about that…
49.
by joppy 5y ago
If you take linear neurons, then the whole network is just some linear (or affine function) of its inputs, and hence the universal approximation fails (not every continuous function can be uniformly approximated by linear functions).
50.
by joppy 5y ago
Why does the function you are approximating need to be smooth? From the paper cited in the article, all you need is for f to be continuous on a compact subset of R^n.
51.
by joppy 5y ago
Start with an unfinished series? Strange recommendation, I’d instead suggest going with one of the more complete stories…
52.
by joppy 5y ago
So reverse a list/slice of anything else then?
53.
by joppy 5y ago
Negative numbers are more obvious though: if you have half a number line (positive numbers) and you want to talk about relative positions of things, negative numbers make a lot of sense.
54.
by joppy 5y ago
The whole approach of Grothendieck (the “rising sea” analogy) is to conquer deep theorems by first conjuring obscure (but simple) objects and prove simple properties of them, again and again, until finally the deep theorem is a result of ma
55.
by joppy 5y ago
Haskell also supports using any old function as an infix function by putting backtics around it, for instance (x `div` y). It’s a nifty feature that can improve code readability (especially in more mathematical contexts) when used well, I w
56.
by joppy 5y ago
Another argument is in regular expressions, where you can see that concatenation distributes over alternation: A(B|C) is the same regex as AB|AC.
57.
by joppy 5y ago
Unboxing is a huge optimisation though isn’t it? No need to allocate when inserting a new item into the queue (beyond the standard allocations which happen when growing a slice), fewer pointer indirections when reading the queue, easier gar
58.
by joppy 5y ago
As long as you normalise by only multiplying/dividing by positive numbers rather than any nonzero number, you’re really working in S^3.
59.
by joppy 5y ago
Great post! Your code example for isHot() seems round the wrong way; also doing something like “return temperature > 100” is probably more idiomatic than using if/else just to return true/false.
60.
by joppy 5y ago
It's very hard to see the patterns in mathematical expressions or equations without compressing the notation down to be very small, which is the main reason this is done. However, mathematicians break complex expressions down into simp

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