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Researchers achieve ‘absurdly fast’ algorithm for network flow

quantamagazine.org

31–40 of 80 posts

Re: Researchers achieve ‘absurdly fast’ algorithm for network flow

#31
So basically they took a greedy algorithm that used a combinatorial approach and transformed it to use a calculus approach by inspiring from a related problem of "electrical flow through a network".

I wonder if it isn't possible to do this for other greedy algorithms, or algorithms which are trying to find optimal solutions through heuristics.

Re: Researchers achieve ‘absurdly fast’ algorithm for network flow

#34

Earlier quoted context omitted.

I've been out of school for a while, what does m^(1+o(1)) mean? Isn't any constant trivially in "o(1)"? So m^1000 is in this class? Or are they using it informally to mean "a very small number"?

The o(1) here represents a decreasing function in m, such as 1/m. (Note: This is little o, not big o.) Therefore, for any k > 1: m^(1+o(1)) grows more slowly than m^k but faster than m

I'm trying to come up with an example to check my understanding. n (log n)^k for some constant k would qualify right?

Re: Researchers achieve ‘absurdly fast’ algorithm for network flow

#35

So basically they took a greedy algorithm that used a combinatorial approach and transformed it to use a calculus approach by inspiring from a related problem of "electrical flow through a network". I wonder if it isn't possible to do this for other greedy algorithms, or algorithms which are trying to find optimal solutions through heuristics.

In this case the "greedy" algorithm was guaranteed to give the best possible flow in the network so this speedup applies to the optimal solution. I think in a lot of cases greedy algorithms are used when the alternative is an NP-hard problem like bin packing or TSP for which we might be looking at speeding up an already sub-optimal solution.

Re: Researchers achieve ‘absurdly fast’ algorithm for network flow

#36

Earlier quoted context omitted.

Yes, only those who can intuitively discover this algorithm are fit to write HTML and JS at this company.

I skimmed the paper, and it makes more sense than a lot of SPAs.

Tax laws make more sense than a lot of SPAs...

Re: Researchers achieve ‘absurdly fast’ algorithm for network flow

#37

Not a comment in regard to this article in particular, but I love Quanta Magazine. Just the right amount of detail for a non-scientist and consistently fascinating subject matter.

Same here. I love that they also cover maths, which few pop sci publications do.

Re: Researchers achieve ‘absurdly fast’ algorithm for network flow

#38

Earlier quoted context omitted.

I'd agree with you ~1 year ago but I think a lot of their articles now tend to water-down lots of complex subjects in rigorous math papers. Still remains one of my favorite websites.

i think they have to water it down so much because hardly anyone would understand the math, even people who consider themselves good at math or have degrees in STEM..it's just so advanced even relative to that .

I think this is probably right. They are among the few to even attempt it.

As someone who loves math but who only knows a little, I find the articles manage to convey the broad ideas quite well. What it is, why it matters. I could stand more detail, but I guess many others couldn't.

Re: Researchers achieve ‘absurdly fast’ algorithm for network flow

#39

So basically they took a greedy algorithm that used a combinatorial approach and transformed it to use a calculus approach by inspiring from a related problem of "electrical flow through a network". I wonder if it isn't possible to do this for other greedy algorithms, or algorithms which are trying to find optimal solutions through heuristics.

Yea maybe for related problems (but not all optimization problems in general).

It looks like this solution works for a specific group of problems. So it won't be applicable to all problems that use greedy (or other) heuristics.

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