14113

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91.
by 14113 11y ago
From a browse on wikipedia it looks like knot equivalence is decidable. If I'm reading [1] correctly however, it looks like strong bounds on the complexity of knot equivalence in general haven't been found. [1] http:/&#x2F
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by 14113 12y ago
Ah interesting! I'll check that out asap!
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by 14113 12y ago
I was thinking about something similar a couple of weeks ago: Wouldn't it be useful to be able to serialise browser state? I.e. saving a full package of html+css+javascript state to a compressed file on a hard disk. Having that ability
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by 14113 12y ago
Compilers (at least optimising ones) bloody well do! For example discrete maths/graph theory for control/data flow graphs or optimisation algorithms for register allocation/loop unrolling. Or, if those don't count as mat
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by 14113 12y ago
A good metaphor that I like to use is to relate computer science as it is now to physics, engineering and maths. All three have a degree of overlap, but each of them thinks about the same problem entirely differently, with different purpose
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by 14113 12y ago
You'd have to change the program? Each agent was stored as a C structure - so adding further information to that would be trivial.
97.
by 14113 12y ago
They were stored as values in a huge array. I fail, however, to see how that causes them to be distinguished from "agents"? Surely they still fulfil the properties required to be "agents" in an abstract sense? They gathe
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by 14113 12y ago
Ah, Boids! One of my favorite examples of systems that can be "embarassingly parallel". I managed to write (with very little optimisation - not even using quadtrees to optimise neighbour lookup) a GPU accelerated version about
99.
by 14113 12y ago
You've exactly proved my point - "future integrations with the GPU/SIMD" - they're not the future - they're now. If you want to leverage them, don't write javascript. Or at least, don't write pure jav
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by 14113 12y ago
I'm a little bit confused as to the purpose of this library, aside from "we would like an abstract linear algebra library". If it's for scientific computing, why is it in Javascript? High performance linear algebra code
101.
by 14113 12y ago
That is what I understood you as saying. I still don't see how my phrasing of the decidability of the halting problem as a complexity problem is any less valid. In any case, it's clear from your appeal-to-wikipedia that this conve
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by 14113 12y ago
Ah yes, you're right - I messed up, and was thinking in terms of strings of symbols, in which case there can be an infinite number. EDIT: Sorry, wait, I was correct all along - as I was talking about the worst case complexity! Consid
103.
by 14113 12y ago
No - complexity theory deals with the "hardness" of problems not of algorithms, and yes, then the bounds on what algorithms we can write to solve them. By that metric (and even by your own argument "the inability for algo
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by 14113 12y ago
Did I say anything about efficiency? Computability itself is a topic within computational complexity, as (in many ways) it's one of the "hardest" rungs of the complexity ladder.
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by 14113 12y ago
It's still necessarily got a worst case complexity of O(n) - e.g. consider the case where the contents of nodes are perfectly disjoint. In that instance, you'd require O(n) space.
106.
by 14113 12y ago
I'd argue that the definition of computability is an instance of complexity theory, which easily predates what we'd call "programming".
107.
by 14113 12y ago
Is there an "autoplay" tag that could be added to this? I tend to open a large number of tabs from hackernews at once, then work my way through them, so it's particularly irritating to be surprised by one that suddenly plays
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by 14113 12y ago
I think a great comparison would be between the British tv show "Scrapheap Challenge", and "real world" engineering. In the show, teams have to compete, over a period of 3 days, to build specific vehicles (e.g. amphibiou
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by 14113 12y ago
Better a few weeks than a couple of years and millions of funding.
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by 14113 12y ago
It may be that their applications have high memory usage, which lazy evaluation would make slightly worse. Alternatively, they may have found that the applications that they tend to run benefit from a slightly stricter evaluation strategy,
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by 14113 12y ago
Regardless of how good the tool is - that was an excellent demonstration clip! Within ~30 seconds I knew exactly what the tool did, why it was cool, and what I might want to use it for. Startup landing pages could learn a lot from that sing
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by 14113 12y ago
Hmm, that's a fair point. Thinking about it a bit more, I think my definitions fit closer with the idea of concurrent or parallel programs rather than the abstract ideas of concurrency or parallelism themselves. In any case, I comple
113.
by 14113 12y ago
I hate doing this, but both the wikipedia articles for concurrency and parallelism agree with me: Concurrency > In computer science, concurrency is a property of systems in which several computations are executing simultaneously, and pot
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by 14113 12y ago
I don't think either definition really defines what concurrency and parallelism are really. Concurrency is the study of how processes interact (i.e. communication, locking etc) while parallelism is studying how to physically perform
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by 14113 12y ago
As someone who owns (and regularly uses) an aeropress, may I ask why? Simply out of of curiosity, not out of disagreement.
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by 14113 12y ago
This comment really sums up the cult of personality that's grown up around Musk.
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Links: Linking Theory to Practice for the Web(groups.inf.ed.ac.uk)
1 points by 14113 12y ago|0 comments
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by 14113 12y ago
The "one langauge for the whole stack" is being developed (for the web at least) through the language Links: https://en.wikipedia.org/wiki/Links_(programming_language) http://groups.inf.ed.ac.uk&#x
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by 14113 12y ago
But at the same time, something that could be achieved by something like Haskell typeclasses, e.g. a "concatenatable" typeclass - which then gives you more polymorphism for free than you originally anticipated!
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by 14113 12y ago
I accept that Arxiv material is generally eventually published, and serves as a staging post for publishable material, however I was protesting to the idea that being on Arxiv in any way constitutes peer review. I note that the lead author

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