skysight-inc/HackerNews huggingface dataset:
Remember linear programs? E.g.

min 10x + 5y
s.t. x <= 10
y >= 5
x+y = 8

(Not very useful example)

Now we can extend normal linear programs to what is known as Mixed-integer linear programming (MILP). This allows us to specify the domain of variables, i.e. we can say variable x must be a positive integer or variable y must be binary.

(This extension instantly makes solving generic MILPs NP-hard because obviously we can transform any e.g. 3-SAT problem into an equivalent MILP problem)

MILPs can also be used to solve the Traveling Salesman (TSP) problem. You use a binary variable for every possible pair of cities or edge the salesman could travel on that specifies if the edge is used or not. Since you want a loop, you also add a constraint for each city that it is entered and exited exactly once using the edge variables.

At this point, you could think we are done: we enter and exit each city once, so we have a loop and since we minimise the sum of edge costs, we also have the optimal loop.

Unfortunately, our formulation is incomplete because it allows a loophole for the solver: doing multiple tours or subtours.

If we have a TSP with 5 cities, the solver could choose the edges such that you have two loops or subtours, e.g. one with 3 and another with 2 cities. That would be perfectly consistent with our formulation since each city is still entered and exited exactly once. It's not a valid solution for the TSP however since we require one single loop, not two unconnected ones.

To fix this problem, we need to add what are known as "subtour elimination constraints". These check that for every partition of our city set into two sets A and B, the cities in A and B are connected, i.e. we have one edge leaving A for B and another returning from B to A (or vice versa).

Unfortunately, since we need to do this for every possible combination of sets A and B, we would have to add exponentially many of these subtour elimination constraints, and of course for very large TSPs even enumerating all sets A and B is already infeasible.

So what is done in practice is to first leave out all subtour elimination constraints, since this is what causes the exponential explosion (so far, our problem was polynomial in size). You then solve the linear relaxation of the MILP, i.e. you pretend that the binary constraints on the edge variables do not exist and use Simplex to solve the resulting linear problem.

Then you create a weighted graph: the cities become vertices, and the edge weights are given by the (fractional) values of the edge variables. For this graph, compute the minimal cut using your favourite polynomial time algorithm. This gives you three things: a partition of the cities into two sets A and B, and a value for the flow between these two sets. If the flow is less than 2, you have found a violation of the subtour elimination constraint for sets A and B. You add that one constraint to the solver (cutting the invalid solution) and start anew.

This process can be fully integrated into a branch & bound or branch & cut solver for MILPs.

(I'm sure wolfgke can give a much better explanation, though)
The Fallacy of Data-Driven in Product Design
I don't have any tattoos and have zero interest in ever getting any, but this seems incredibly judgemental. Some of the most normal and boring people I know happen to have tattoos.
Yeah I actually don't think the human brain accounts very well for time. Like despite a decade has passed I don't feel as if time has moved very much for me. Despite the fact that people age, it does not seem an inbuilt thing to recognize your age. It just seems to be something that happens to your body.

Thinking a bit more about it I don't think the brain accounts for time in long term memory, it does a better job in short term memory. That's why a musician can use time and we can't use it very well for stuff we stored a week ago.
Kerosene lamps were ubiquitous before electric lighting. Look at the pictures in the wikipedia page[0], you'll recognize them for sure.

[0] https://en.wikipedia.org/wiki/Kerosene_lamp
Yep, and there is no incentive to create new homes. Except for airbnb.

Why would you create a new home when you just can increase the rent?
No, that's what a zero knowledge proof is; at the end of the protocol, you are convinced that some statement is either true or false, and learn nothing else about the "proof".

In NP-terms, you learn whether the NP instance is true (eg a 3SAT clause is satisfiable), but learn nothing about the witness (eg the assignment to the clause's variables).
Why Gold? (why gold became currency, part 2)
Firefox article reader mode kills pretty much all of that s*. It also makes articles much nicer to read, IMO.
> Those languages used to introduce mutable wrappers and not a "to_string()" method.

Yes! This is similar to, say, StringBuilder in Java. The difference is that ownership is intertwined with the type here. Strings are always owned, and as such you can choose to mutate them. String slices (references) are not owned by you (you borrow them), so you can't do anything that would be memory unsafe. You can borrow a mutable slice of the String (like a reference to the backing array), which you can alter in-place but you cannot do anything that would require reallocation (Strings being growable was mentioned earlier -- mutable slices are not). Slices which come from string literals are always immutable.

For probably-obvious reasons you can only take one mutable reference at once, while you can have as many immutable references as you like. Taking a mutable reference also prevents you taking any immutable references at the same time: https://doc.rust-lang.org/book/references-and-borrowing.html...

In my own experience this takes a bit of time to get used to, and in some cases the rules are still quite frustrating. People with more experience of the language report that they get used to it, though.

> Is that similar to the dynamics of uniqueness types?

I believe it's similar, but I'm not super-familiar with uniqueness types. This SO answer looks good: http://stackoverflow.com/questions/26309081/how-do-rusts-own...
A Year of Hackathons – talking to people, making dumb stuff and why I love hacks
I don't remember any magazine with that crap, but maybe it's a regional thing, I'm not from the US. Which ones are you thinking of?
>> But that's just me. It could be totally different for someone else

It is. I haven't eaten breakfast for 20 years, and I don't suffer from any kind of lethargy, tiredness or hunger. I even cycle to work for 30 minutes each day, on an empty stomach, and often don't eat until 1PM. For me, it's actually the other way around: if I eat anything before lunch time, especially sugary things, I often get nausea.

So I guess that confirms your point, there simply is no 'one-size-fits-all answer', everybody has different metabolism. Obviously some things are clearly bad for you, like overeating, insufficient dietary variation, lack of essential nutrients, etc. But these are simply solved with just common sense. For the rest, 'nutrition science' is completely worthless IMO, and more often than not driven by marketing or scientific echo-chambers.
How Companies Use Big Data to Deliver Extraordinary Results
Sunsetting API v1 in Favor of CloudFlare’s Current Client API: API v4
> Which kind of metric is it used to compare these algorithms?

Usually (in particular if the edge weights in the graph are non-negative or even positive) the ratio (or sometimes, but more rarely, also the difference) between your attained solution and the optimal solution.

> How good are heuristics methods compared to exact solvers?

First: For mathematically minded people "heuristics" (in the sense of the video) are to be considered worthless since you rarely can prove anything about the solution attained by it. Even if by definition some result about the solution can be shown (say, that it is optimal in some k-neighbourhood of solutions) this will hardly tell you anything about how good you really are.

But one very good heuristic algorithm for which you actually prove something (and thus is really helpful) is the Christophides algorithm (https://en.wikipedia.org/wiki/Christofides_algorithm), for which one can show that if the edge weights form a metric in the graph you will get a solution that is at most 3/2 as long as the optimal solution.
We Need to Know Who Satoshi Nakamoto Is
Startup Mentors, a Love Story or a Nightmare?
Kanban or Agile?
Yes, limited in scale and scope, much like World War II, or the Second Congo War, both of which occurred without the deterrent of nuclear weapons.
Check out how DigitalOcean does this, on their tutorials. As you scroll down, a small box appears in the left margin asking you to sign up for the newsletter. It doesn't block any of the content and you can ignore it while you continue reading. That's nearly perfect, and an example of how to do it right.

I still find the animation of it appearing distracting and I think it interrupts the 'flow' of reading the article, but it was easy enough to block the element with my ad blocking extension.

As an aside, Firefox + Noscript are a thing of beauty. Using them I just don't see most of these annoyances. Yes, it 'breaks' many websites but this usually means a much faster page render without all the annoying stuff.
Dealer TV
I should love Node.js for these three meaningless, generic catchphrases?
I believe the parens are off by one in the Clojure example and that it should be:

(- (+ 1 (* 2 10)) (/ 12 3)) ;=> 17

I've found the threading operator can help in these cases.

(-> (+ 1) (+ (* 2 10) (- (/ 12 3))))

Or, line breaks can clarify:

(- (+ 1 (* 2 10))
(/ 12 3))

or at the risk of overdoing it:

(-
(+ 1 (* 2 10))
(/ 12 3))

Now I know at first glance that I'm subtracting the results of those two lines from each other.
Indeed the last two might be almost as clear as the infix, and are without any order of operations rules.

Also some don't like colored parens but I find them very clarifying.
It seems that, in trying to make a second point, jgrahamc accidentally proved his first.
New JavaScript: ES7 and beyond
Wow, that is a cool website, they have all the internet on their webpage and one can search for things, great startup idea!

I spent hours browsing their results, and still have many more pages to go. Thank you very much for that, I was so bored and now I have something to spend my time with, I feel much better now!
New Product Development Process
I guess it depends on your definition. It would seem that, from a layman's perspective, ETFs and ABSs are both derivatives. If we look at GGP's comment

> Buy up crap, package and obfuscate it, then sell it off as "high quality" crap to investors desperate for yield.
Mac OS X pkgsrc binary packages now following a rolling release model
People also live longer. Social security (retirement) was never intended to support people for 30-40 years. The age has to go up with the life expectancy to keep it solvent.
Clothes are petty expensive tho
强烈推荐自己用的 GitHub Star 分组工具,开源的
App Dilemma Solved in 5 Minutes… Native vs. Hybrid vs. Web
Right, OP wasn't saying that we had never been _beyond_ GEO, but never been to the orbit - going through is a lot easier than stopping off partway.
I think you'd be surprised by how many there are.
The problem is that as long as the kernel is proprietary, people have no reason to trust it to run that kind of hardware.
Acesso gratuito de seis meses ao Netflix é golpe
> Yeah, but what will your tatts look like when you're 80?

Which is a good point. Current tattoos are also limited in life span. Even before a person dies, the tattoo will start to blur. So really these guys are just lowering the life span of a tattoo to something within a persons life. Which is already a thing since you can get tattoos removed by laser.

So all they have done, should they succeed is make things more convenient.
> fucking light-box

I completely agree.

I turn off javascript for sites that have light-boxes or large top-bars. It's worked well for sites like priceonomics, which appear on HN intermittently. In case it's helpful, the one I use is "quick javascript switcher":

https://chrome.google.com/webstore/detail/quick-javascript-s...
ok I'll remember it for the next time I chat with you. But come on dude, most people don't care about the distribution I use, knowing that I use Linux (the OS, not the kernel) and not Windows or OSX is what they want to know. All the rest is literature. Really.
Don't worry, this was 2002. It'd be like jousting with a couple Proliant G3s or something.
… based on one statement by one person.
There's a key statement here that most will either miss or never reach. The second last paragraph

> Machine Learning Automation

Tuning models is a pain, and if you don't understand the model and all its parameters (like most software engineers who's job is the write software and not build models!) it takes time and can be immensely frustrating. Randal Olson[1] just announced TPOT[2], a Python tool that "automatically creates and optimized machine learning pipelines using genetic programming". This is going to be a huge lever for engineers wanting to experiment/implement with ML algorithms.

[1] http://www.randalolson.com/2016/05/08/tpot-a-python-tool-for...
[2] https://github.com/rhiever/tpot
This is also a common complaint about Simple English books written for English learners. The books claim to have a restricted vocabulary, but they cheat by using phrasal verbs.

Their vocabulary includes verbs like put and set along with prepositions like up, with and upon. You can combine these to generate an enormous number of phrasal verbs like put up with, set upon and so on, which are normally considered to be separate vocabulary items.
Since you're keen on giving advice, I'll bite, how would you describe NAWAPA to others?

The way I see it, no matter which way I described it, I knew there would be commenters who would have a visceral reaction when they learned about the project's externalities. There's a reason this project was killed before getting anywhere. Hence, I knew full on when writing the grandparent comment there would be that kind of reply, from people solely letting others know how much they disagree with the project.

I don't see much value arguing with these commenters, because they've already decided their opinion. And I gain no benefit convincing them otherwise.

Obviously, based on the votes on the grandparent comment, some people did find what I wrote interesting or insightful enough to upvote. But it did bring out many unhappy posters. How would you have handled it?
It could be unflagged by the moderation staff.
What's wrong with tribal tats on whites guys? They had as little to do with the invention of those patterns as the descendants of the originators; Are tatoos limited to signalling personal perception of identity?
Nothing I said was wrong.
It was better back when it was urban spoon. Much better, sadly.
Are you going to uncensor it?
Best i can tell, is a "developers developers developers" thing. The goal is to present a set of APIs that abstract away the underlying OS.

Sadly though this has been done multiple times over, but then discarded because of CADT.

Pop over to Freedesktop.org and you will find the remains of a number of discarded projects. Most of them discarded just as they are 99% feature complete and the devs face the prospect of doing janitorial maintenance.
Take a look at this commercial Obfuscator for x86 code https://www.pelock.com/products/obfuscator
TPOT: Automatically Optimize ML Pipelines with Genetic Algorithms
Diagnosable validity
Projects in php mysql
I believe most people adds the readability extensions. Which is a more sophisticated and produce more elegant results, but printfriendly is very fast, non invasive, and very effective at getting content without clutter. 0.01% errors, and the team reacts rapidly when it happens.
What is then?

One thing that's always bemused me is that YC doesn't insist on its companies using Lisp :-)
Nice! This is a product that I have contributed to while at fb, and it's cool to see it getting some attention.
Target=”_blank” – the most underestimated vulnerability ever
As scott_s pointer out $50-100 was just the price of this special ink. So for the extremely small tattoo price you're quoting this ink doubles the total cost and only lasts 1 year.
It's not only self-driving cars that use software.
Strange because the DLR is almost completely automated (no driver, but ticket inspector closes the doors) and has no platform edge doors. But they do have emergency stop buttons on the platforms.
Looks like something that will slowly reduce your ability to see with that many LED's shining that powerfully into your eyes.
Looks great...
unless leftpad gets withdrawn from npm again
No, you're spot on. I just finished this book. The computer was used to generate nonsense, which they used as a creative prompt when they were at a dead end in the 'Plan'.
I disagree. Tattoo's may be more accessible for the person buying in that more people are willing to take the plunge - but the number of artists isn't going to increase. And the time a tattoo takes to complete isn't going to decrease. Essentially demand will increase (quite significantly) and supply will remain the same. So prices will increase. It takes many years to become a good tattoo artist and even a small tattoo is quite a time consuming procedure. There's little that can be done on the supply side to increase it.
> 2) provide a paper or thesis which illustrates your point?

The typical recommendations about this topic are

Schrijver: Combinatorial Optimization - Polyhedra and Efficiency; Volume B, Part V, chapter 58

(often called "the bible of combinatorial optimization") and

Korte, Vygen: Combinatorial Optimization - Theory and Algorithms (5th edition, not that this should make a difference); chapter 21
I was actually eating cereal as dessert for a while and got into as bad a habit with it as I previously had with ice cream. It took a concerted effort to break myself of the habit.

I think I even enjoyed it more than ice cream, even if it was raisin bran or something. (Though I usually add a sweetener, currently Stevia rather than sugar.)
It wasn't an accident. I was showing that the ambiguity introduced by his language means that it's hard to understand what's really going on.
I can't install extensions here, so that's unfortunately a no-go for me. This looks like the next best, least intrusive option
Hedge Funds Faced Choppy Waters in 2015, but Chiefs Cashed In
> I started forcing myself to eat breakfast

I tried that when I was having lethargy problems mid-morning, but my digestive system doesn't seem to switch on until a while after waking up and if I consume anything more solid than milk before it tells me it is ready I get unpleasant indigestion feelings.

I tend to get hungry and have my first food at ~1030 or a little before. The exception is the days I have a long run into work (a 7.5-to-10K slow run, instead of the usual 2ish Km walk) - I want food as soon as I've showered in that case.

Exercise before work has itself cured the lethargy problem it would seem and it doesn't need to be as strenuous as a 7+K run. Just the difference between the old routine of cycling in, to doing a few situps & dips before getting dressed and briskly walking in, seems enough to make a marked improvement even into the late afternoon.
What it takes to launch an app
IDM 6.25 Keygen Build 14 and Full Crack Final Download
People are afraid the cars will follow traffic laws, and drive legally, even when no one else is? And, I find it hard to believe that everyone disobeys the posted speed limits on freeways. For example, trucks with speed-limiters, people who don't want to break the law, buses, etc.
Interesting theory on asthma. I also wouldn't be surprised if it was one of those things that just gets diagnosed a lot more than in the past. For example I've been diagnosed since I was around 10 but despite it being quite bad when I exercise I rarely use medication and have never had an attack. I get out of breath much more easily than a regular person but I'm guessing in the past it just wouldn't have been diagnosed as there was really no episode that led to the diagnosis other than the doctor measuring the strength of my breath during a routine visit I believe.
In fact, i sometimes did the reverse: found clients outside of Upwork and brought them in. I am even more likely to do it now since June 1 when the commissions drop from 10% to 5%. Upwork provides guaranteed billing... It is extremely difficult to extract payments when nobody does it for you.

Enterprise pricing page - good idea, i will tell Maxim (owner).
upd: he said that in fact decisions on buying it is usually taken by IT department heads who then massively rework the system for their own needs, so a higher priced sale would be impossible, in many cases they already prefer open source.

In fact, even selling whole company failed through - interested buyers who definitely had money, eventually refused to pay even $100K. Working on Upwork has definively been way more productive activity.
You would need to add support for skip scans to the query planner, and adding feature to the query planner is rarely simple.
I probably should have linked to this story:

http://gizmodo.com/former-facebook-workers-we-routinely-supp...

But not just one person - Facebook had to apologise to John Dickson for deleting his post. So I ask you - what were they doing fooling around with his posts?
Can anyone explain: why are government works automatically public domain (not copyrighted) but government inventions are not unless explicitly stated?
Yes, I thought pig tattooing as a spectator sport died out in the 70s.
How to use your PS4 as a media streamer with or without DLNA
Hm, fast bulk write is an area where PostgreSQL generally handily beats MongoDB. I do not see why it would be different for geodata. MongoDB beats PostgreSQL for some things, but not bulk load.
The UK has a few sleeper trains, where you get a proper (if small) cabin with a proper bed etc. They run from London to some of the major cities; I'm particularly fond of the London-to-Inverness sleeper (the buffet car does a killer haggis).

Cost wise, it's considerably more expensive than an Easyjet cattle-car class flight.

But the big benefit is that it takes no working-day wall clock time. I can leave the office in London after work, comfortably reach Euston where I board the train and settle down in the buffer car with a drink and wifi; then I arrive at Inverness at about 0700 the next morning, refreshed having slept well. All the travel happens while I'm asleep.

Conversely, flying Easyjet takes waking time. I have to leave the office in the middle of the day, get to the airport, wait, check in, wait, board, fly, and arrive at my destination still during waking hours --- it eats most of an entire day.

I can't tell how this bus would compare against an overnight red-eye flight, because we don't have those (the UK's not big enough!). But I imagine that having a bunk would mean that I could actually sleep on one of these buses, unlike the fake sleep you get on planes. I'd definitely consider this, even if it was more expensive than the plane.
I'm not particularly surprised that it's written in Python.

- Lua/Torch appears to not be designed for distributed systems as much, and looks less mature in terms of the scientific computing side.
- PHP is clearly the wrong tool for this job - it's only really the right tool for websites (debatable).
- Could do Node.js, but has little/no data-science/scientific computing side.

C++ would be the only reasonable competitor to Python here I think. Python is a pretty good combination of great for science, good for servers and easy to pick up and use for all the engineers who will need to interact with it.