skysight-inc/HackerNews huggingface dataset:
I think it's worth noting that the problem with numerical differentiation, fundamentally, is that differentiation is an unbounded operator. In finite-differences, (the more obvious approach), you assume that your data are samples of some, general, function.

The problem then, is that that general functions have no (essential) bandlimit [1]. Remember that differentiation acts as a multiplication by a monomial, in the frequency domain [2]. Non-constant polynomials always eventually blow up away from 0, so in differentiating, you're multiplying a function by something that blows up, in the frequency domain. This means that, in the result, higher frequencies are going to dominate over lower frequencies, at a polynomial rate.

Let me be clear, the problem with numerical differentiation is not just that rounding errors accumulate, it's that differentiation is fundamentally unstable, and not something you want to apply to real-world data.

It depends very much on what your application is, however, I think generally a better approach to AD is to redefine your differentiation, by composing it with a low-pass filter. If designed properly, your low-pass filter will 'go to zero' faster (in the frequency-domain) than any polynomial, thus making this new operator bounded, and hence numerically more stable. It's not a panacea, but it begins to address the fundamental problem.

One example of such a filter is Gamma(n+1, n x^2)/Factorial[n], where Gamma is the incomplete gamma function [3].

In Python:

scipy.special.gammaincc(n+1,nx2)
or
mpmath.gammainc(n+1,nx2, regularized=True)

To see why this is a nice choice, notice item 2 in [4]. This filter is simply the product of exp(- x^2) (the Gaussian) multiplied by the first n-terms of the Taylor series of exp(+ x^2), (1/ the-Gaussian). Since this series converges unconditionally everywhere, as n-> +infinity, this filter converges to 1 for a fixed x (as you increase n), however, since it's still a gaussian times a polynomial, it always converges to 0 as you increase x, but fix n.

This is my area of research, so if anyone's interested I can give more details.

[1] https://en.wikipedia.org/wiki/Band-limit
[2] https://en.wikipedia.org/wiki/Fourier_transform#Analysis_of_...
[3] https://en.wikipedia.org/wiki/Incomplete_gamma_function
[4] https://en.wikipedia.org/wiki/Incomplete_gamma_function#Spec...
Building things on top of docker seems like the fun, exciting thing to do these days and the promise of it is really cool. I certainly have wanted a private heroku that is not a bear to install.

In my ideal world, you could start with a single machine on say Digital Ocean for $5/mo. and that machine could host any number of apps, heroku style, for me until it runs out of resources. It should then be easy to move apps to a 2nd or 3rd or whatever server if I chose not to just bump up the resources on that first one. If an app needs to run multiple servers, it should handle that as well. Having reasonably fine grained control on how many machines things like a database or memcache layer was on would be nice.

In short, I would like something like heroku without all the extra costs of heroku. Cloud 66 comes reasonably close, but I'd like to not pay the extra service overhead. I'd rather just pay for the infrastructure. Something open source that handles this in a reasonable way would be great, but I don't know that Deis is going to be the answer.
That's where the analogy falls apart, people who only eat out are a small percentage of the overall popular whereas people who only need a tablet are purportedly the norm.
The string concatenation in this make me want to cry...
Clojure jobs at Staples Innovation Lab
There must be a distinction between deliberate effort and flow effort? One weird thing I note is that reading highly technical articles online is easier to make myself do than reading technical papers (even if the article is roughly as difficult). It's like the same task but the classification causes me to make different decisions.
this was my initial though... any big brand who owns a trademark is probably going to find this useful, and I can't imagine someone searching "dell" or "southwest airlines" who isn't simply looking for their main site.

If these ads show up when you search "cheep airline tickets" or "personal computers" i could see there being a problem.

Does anyone know what you need to do to qualify for that type of banner ad? My guess is trade mark and major brand recognition
Want CoffeeScript
Apple Just Cannibalized the MacBook Air
Is it just me, or does this look very close in design (and even placement of specific buttons) to Metalab's Ballparkapp (http://www.ballparkapp.com)?
GitHub and Behance visual stats for Developers and Designers profiles
"TrueCrypt is a project that doesn't provide deterministic builds."

Why? What is the benefit of doing so when everyone wants a deterministic build?
I didn't see Ctrl-r, but I've found that to be the most insanely useful shortcut.

Ctrl-r = reverse history search. Type a partial command after Ctrl-r and it'll find the most recent executed command with that substring in it.

Press Ctrl-r again, jump to the next oldest command containing your substring. Did you accidentally press too many Ctrl-r? Press backspace to move forward in history.
Actually, discovered ledger-cli here last week (thanks HN). It's amazing. Abstracting currency to the concept of commodity + price files makes it trivial to track your shares in 401k, and have the current market value print on the balance report. Handles lots. Recurring transactions support period specifications like "every two weeks starting on 2013/10/01". Maps payee's to accounts, and supports payee aliases. Pretty much anywhere you type a string you can also use a regex. State is a text file and the program does not alter state; just reads it and prints out a report. Finally, it provides a CSV convert which makes it easy to convert an export from your bank to a list of double entry transactions (./convert bk_download.csv >> trx.dat).
Here’s All You Need To Know About Conducting Customer Interviews
You probably own a really nice PC but most people do not. I'd wager that an iPad is at least as expensive as the PC that it is replacing in most homes.
It would defeat the purpose of Bitcoin if it replaced Bitcoin. Since it would be built on top, it's just a service on a cryptocurrency foundation instead of whatever your government prints.

In that case a credit/debit card could basically be an immediate guarantee of payment (3rd party guarantees, collects small % to cover abuse/running costs. basically credit cards now, minus chargebacks), as opposed to what Bitcoin provides.
It has got me in touch with a couple of college friends I had lost touch with, a former co-worker likewise, maybe a cousin.

Business value? No.
That's the thing...most games are still not multi-threaded well, and single threaded performance hasn't gone up more than maybe 20-30%, they just tacked on more cores.
everyone I know has a 64-128GB SSD and a 1TB internal HDD, and a 1TB external HDD for backups.
Don't duck, it's the truth.

We built really powerful computers and decided the best way to use them was to run web apps consisting of a poor performance scripting language with a poor performance visual-rendering language and half the people who build with it seem to think that anything done in a web browser is free.

"Modern" CSS for even a simple site is pretty silly. So many horribly inefficient rules, sometimes dozens of levels of overwriting properties, etc. And gobs upon gobs of Javascript that does very little but is constantly running, checking input boxes, animating every tiny little detail, doing things that can be done without Javascript, etc.

I have better system performance when running a Windows 7 VM, a semi-bulky image editor, or compiling the kernel than I do with a few bulky webapps in Firefox. And this is on a desktop built just 4 years ago.

I have a light-weight Linux setup that uses 80MB of RAM after logging in. It has 1GB of RAM. I can't run GMail and Facebook Firefox and browse the Internet at the same time with minimal open tabs. It's sad.
I totally see what you are trying to do and think you are kind of right. Considering I have multiple win XP machines that I am still using today says alot.

On the other hand, hardware is cheap and think ChromeBooks (https://www.google.com/intl/en/chrome/devices/chromebooks.ht...) will solve this need

I would recommend giving it a try by showcasing 1 and saying it and if you sell one - tell them to come back tomorrow to pick it up and spend the evening making it work.
Cubes of frozen alcohol might work. Maybe with a little frozen C02 mixed in for certain drinks.
goolge quote:

“There will be no banner ads on the Google homepage or web search results pages. There will not be crazy, flashy, graphical doodads flying and popping up all over the Google site. Ever.”

http://googleblog.blogspot.co.uk/2005/12/about-aol-announcem...
future is distributed unevenly. some retail outlets are still in the past.
Julia's role in Data Science
More like impossible. The Internet has many PC building communities and none of them could do it. Hell an i7 and good GPU at the time easily brought you over 600$, which means very little money for a motherboard than can keep up.
This mirrors my own experience using go to write software used in biological research. Performance is good enough and the quickened dev cycle due to less verbosity and excellent tooling makes implementing variations on algorithms easy.

Ie I wrote a random forest implementation [1] and i've been able to quickly add in a bunch of different published and experimental variations on the algorithm as needed for the data sets I work on.

[1] https://github.com/ryanbressler/CloudForest
Our MMO game, Star Sonata, is also in the same sort of genre, though it's top down-ish more like Star Control, and we have a lot of economic emphasis on building colonies, stations, and automated trade slaves that run your economic empire while you're offline.
I agree... three slightly different shades of grey? Since it is for the OS and Apple's own application, I would think that sticking to one shade each of their main colors (e.g. blue, red, green, purple) would be better. So many colors seems a little over the top and difficult to communicate in a style guide which could get mixed up and cause confusion for users.

I've heard across the interwebs that the color scheme for iOS 7 was something of a circus. I hadn't noticed it yet but this page just put it out there.
Well now, at the moment it is just a pilot program (heh)

But lets assume it doesn't say that way and someone around here needs to search for something like oh

Visual Studio (something or other)
Xcode git integration

Now imagine the glorious Microsoft or Apple ad covering 88% of the screen.

Still don't see the problem? An ad targeted the way this one is isn't useful for anything other than gauging reaction. For it to be useful they will have to show up on related searches, not ones that are specifically for that product or service.
"why do you want to get an ad for Southwest Airlines"

From what the example shows it's not so much an ad as a really quick way to visually see that when you click you will be going to the right place.[1]

I mean visually it's probably quicker to see the big honking ad and airplane and focus and click than it is to read type. I'm guessing. User testing would prove or disprove this. (After all why do people use icons for that matter?)

[1] If it looks like a duck and quacks like a duck, it's a duck.
I'm skeptical about the energy claims. How much of a difference is the continuous cooling of a can of beverage going to cost when you still have to keep the refrigerator running anyway?

Plus energy grids prefer a gradual and predictable energy draw than a sudden spike. Otherwise we end up with scenarios like this:

https://www.youtube.com/watch?v=slDAvewWfrA
Tldr: Binaries didn't match, here's some handwaving at the differences.
Flickr gives you a terabyte free.
They also use a unique license that is incompatible with most other open source projects. They seem to have strong reasons for doing things the way they do, and aren't fond of explaining them.
I can't speak for anyone else, but I find that a little evil.

I'm having a hard time not reading this as effectively saying that it's evil to compensated for providing a service.

Yeah, it's probably the most relevant result, but it's giving the user (especially if that user is, you know, non-technical) little choice but to click on the thing that puts money in GOOG's pocket.

But the user made the choice to use Google in the first place. If people don't want Google getting money for clicks in their search results, then they should use a competing search engine.
VPN is a tunnel, not a MITM. It's used to bypass our monitoring and filtering. You're tunneling out of our network into someone else's, which may have more favorable rules.

This is a MITM, because LinkedIn is intercepting and modifying the traffic between the email server and the client machine, traffic which is supposed to only be read by the recipient. A VPN isn't intercepting traffic, it's used to tunnel traffic. LinkedIn is positioning themselves directly between the traffic source and the destination to read and modify the transmission.
Divorce is never easy: split a project subfolder with Git - longaccess.io
Official Node.js support
Sounds like a bunch of "core" people could get open source contributors, then muscle the votes so no one gets paid.
Deterministic builds are hard...really hard. The combined power of the Debian community has trouble getting deterministic builds, as does the Tor project.
Pico-ITX SBC runs Android on quad-core ARM SoC
An "All You Can Eat" College Degree Could Be The Future Of Higher Education
I think that's inaccurate. The disassembly of them matched perfectly.
"but I suspect it will still be upvoted and discussed here"

Sometimes when there is a story that is a day or so old it's almost as if it doesn't pay to comment for that exact reason.

Edit: By "exact reason" I mean an old story with 200 comments isn't as attractive to make a comment on as a new story with 15 or 20 comments that is 2 or 3 hours old.
No innovation would hardly die but hopefully focus on something important. We will hardly run out of need for innovation any time soon. We rather have a problem of innovative people focusing on the wrong things, because incentives.
Got my 5S in the mail last week.

This makes me want an Android. Great job, guys!
Tools that helped me keep organized while travelling
I find it funny how you think of differentiation in terms of "frequency domain", "bandlimit" and "filter". Very signal-processy, very engineery. A mathematician would speak about unbounded operators in a Banach space. :-)

Edit: Reminds me of the list on page 3 here: http://arxiv.org/pdf/math/9404236v1
I wonder if you wound up the sock and let it spin if you'd get something virtually equivalent to this machine.
Why Beer Bottles Erupt When You Tap Them
I just tried it.

I count:

1 Big ass ad
3 "News" items
5 genuine "Search Results" (with no heading or any way to know when the ads and nonsense stops. One of the 5 is a link to the Southwest Airlines Android App
3 "In-Depth Articles" I don't know what this is, i guess long blog posts?

This honestly looks more to me like a domain squatting BS ad page that we hate on ISPs for than a research tool (which is what I used to think of google search as).
"Apple SEC ruling" is a fairly specific keyword search whereas searching, blanketly, for a company name is not.
Dietary Fat and Heart Disease
Amazon Enters the Flash Sale Fray With Myhabit
That's misleading, because they are counting the whole result box that is labelled "Sponsored", but of that box, everything but the actual graphic banner at the top of the box is exactly the organic search result which is the top hit for the search (including the subordinate links) served to users that aren't getting the new experimental ads. So, everything but the graphic (not everything but the sponsored box) is "actual Google results".
I use my 2009 iMac for local heavy lifting and watching TV. (Heavier lifting I use the cloud.) I will upgrade my desktop once the LCD goes retina.

I will continue to upgrade my laptop frequently. Lighter, smaller, faster, longer lived, more durable. Every new laptop has increased my productivity, flexibility.

I just bought a 2013 MBA 13". Most amazing machine I've ever had. Now that I'm accustomed to 13" (vs 15"), I will likely buy a 2013 MBP 13" retina. I'm certain that I'll be very happy.
But isn't the main purpose of personal finance to influence spending decisions? An ideal solution simply just answers the question "Can I afford to X?"

I've not used any software that helps solve that problem in an elegant way, and maybe I'm just minimizing the problem, but it seems like every path to answering that question is simple arithmetic provided you know what other expenses you have in addition to X.
Many of the solutions they highlight can actually be solved with this. Surprised that it wasn't included.
MySQL 5.6: no testcases for non-crashing bugs, either (and an incomplete bugfix)
Just a word here - fish oil supplements are being looked at seriously as a culprit in many cases of prostate cancer:

http://www.forbes.com/sites/stevensalzberg/2013/07/23/those-...
> From what the example shows it's not so much an ad as a really quick way to visually see that when you click you will be going to the right place.[

The banner at the top of the box is a traditional (and somewhat large) banner ad.

The rest of the content of the box is exactly what you get as the top result of the same search on Google when you aren't getting the experimental ad.
You're right, it is begging the question, for any simple function, you basically have to tell it what all the derivatives are for it to work.

The power of this technique is that it handles the product rule and chain rule for you, so composition and multiplication of functions work automatically without extra work.

For the case of 1/(1-x), you only need to tell it the derivatives (wrt x) of

f(x, a) = x * a

g(x, a) = x + a

h(x) = 1/x

Then it automatically knows how to compute the derivatives of h(g(f(x, -1), 1)).
"“We have worked with the insures and the ‘alpha teams’ we jointly established made up of insurers’ technology experts and CMS technology experts, to iron out the kinks,” said Press Secretary Jay Carney in an emailed statement...."

Anyone out there ever heard of "alpha teams" in this context?
Perhaps people invested in Google precisely because they believed in googles vision for a better web. Google has been fairly clear in telling investors, hey there's a line we won't cross. They can't complain. If there's something to complain about, it's sitting on $50 billion in cash and not paying a dividend.
1. this is a big responsiblity. Are you really signed up for this?

2. You curate the ideas? Doesn't sound very open to me. What about voting? How can you make this more democratic?

3. I'm not convinced these projects could gain traction against a dedicated team of people lead by experienced people in the industry, paid a full time salary, with the sole purpose of making a profit. I would imagine that the open-source "everyone gets paid" thing is where this idea will fall flat on its face. Not sure it will get there though, because this process has to produce an app that generates revenue above operating costs first.
Oh! I thought that was the norm. Author made it sounded like TrueCrypt doesn't and others do the way he said it.
Steal Eggs: The Secret to Scaling A Marketplace
Should Banana Republic be able to buy an enhanced search experience for people searching for "banana republic"?
> Prismic.Api('https://lesbonneschoses.prismic.io/api', function(o) {

> api.form('macarons').ref(api.master()).submit(function(result) {

Nice. I've always wished for my javascript callbacks to never encounter any errors too but couldn't make it happen... Maybe you should patent that instead?
> Curious: does everyone in this thread have equal outrage for those widgets that log into your email clients so that you can invite your friends?

Yes, there has been much rage against that type of service on HN.
Spin Chill [1].

1: http://www.kickstarter.com/projects/1139594493/spin-chill-wa...
That would be a great way to increase the amount of fraudulent studies being published.
This would not qualify as a branded search term, so this extension would not be available.
It's a desktop. I've browsed the Sunday ads for Best Buy and Walmart and it's common. Example:

http://www.walmart.com/ip/Gateway-Black-SX2110G-UW23-Desktop...
> 1. Instant on. I can keep my thoughts in tact and act on them immediately. No booting, no memory lags, no millions of tabs open in a browser.

Suspend to RAM, 8 GB of RAM and as many tabs open as I like (usually none, but Opera appears to handle 100s quite well, too). You must be using PCs wrong.

> 2. Focus. Desktop interfaces seem to be desperate to put everything onto one screen. I have a PC and a Mac (both laptops). I prefer the PC to the Mac; better memory management for photoshop and browsing, and I love Snap. But that's where the usefulness stops. With an ipad, I have no distractions on the screen.

I also have no distractions on the screen if I don’t want them. You must be using PCs wrong.

> 3. \…] The iPad Mini is better than the bigger variants. […] I don't need a big screen for a PC because the resolution isn't better than an ipad and I'm using it solo. Google Glass could quite possibly be the next advancement in this theme.

The iPad mini has a resolution of 1024x768, roughly the same as my X41. If your current PC doesn’t have a higher resolution, you must be using PCs wrong – I expect at least 1200 pixels vertically and 1400 horizontally if I am expected to do any work at this thing. 900 vertically might be enough for casual browsing, but it does feel inferior.

> 4. Build quality. PCs look and feel cheap. Including my beloved Sony Vaio Z. The ipad in my hand could never be criticised for build quality.

I tend to be very wary around Apple hardware, seeing how people put them into protective sleeves, pockets and all other assortments of stuff. I don’t think a tablet would survive the things my T410s survived.

> 5. Price. The ipad doesn't do more than 10% of what I need to do. But, I do those 10% of things 90% of the time. So why pay more for a PC when the ipad has no performance issues and takes care of me 90% of the time.

I won’t argue about performance issues (the iPad lacks the software to even test performance properly…) and at least I pay for a PC because I want 100%, not 90%, of the job done.

> 6. Always connected. It strikes me as absurd seeing laptops on the trains with dongles sticking out. It takes ages for those dongles to boot up. I used to spend 5-10 minutes of a train journey waiting for the laptop to be ready. My ipad mini with LTE is ever ready. And cheaper. And built better. And more fun.

Time from button press to xscreensaver unlock window: 2s. Time to get LTE modem ready: 5s. Time to open 100s of tabs in Opera and decrypt email locally and do all other things I could possibly want to do: nearly instantaneously. With an iPad mini (which would most likely break in my backpack on the way to the train), I couldn’t even do half of these things – it admittedly might be cheaper, though, but 1600 € every four-or-so years vs. 480 € what appears like every year are roughly equivalent, wouldn’t you say?

As I said, if you settle with inferior stuff and use PCs as absurdly as described by you, I can see why you like tablets more.
> Sometimes when there is a story that
> is a day or so old ...

Indeed, but in this case the other submission is just 4 hours old.

I had a rant about this in another comment:

https://news.ycombinator.com/item?id=6606955

As I say, this rampant duplication (which I admit doesn't happen often, but still often enough) offends my sense of taste. I know others don't care, but it irritates me.

And now I'm going to have to step away from the keyboard and let it all die down and go away. At least with on-line irritations like this you can just walk away.