Want your own Github? Check out the open source Gitorious. - <AUTHOR> http://gitorious.org/projects/gitorious

<comment><USER2> Seems like somewhere between Trac and Github. I'd like to see it integrate with TicGit; that would rule. Trac's tickets are nice but having tickets integrate with the repo itself and being able to mess with tickets when offline or unable to reach your Trac installation is super nice. Especially if you're working on a project for a client, having them be able to open tickets is a huge plus (AFAIK TicGitWeb doesn't do this or integrate with gitweb/cgit/Gitorious.)

<comment><USER3> Take a look at Redmine (<http://www.redmine.org/>). We're using it for all our internal projects. The git integration is a bit sparse at the moment. You can't browse around branches. But the basics are there.

</comment></comment><comment><USER4> The killer feature of github for me is their network graph.. it would be great if they could copy it, and open source it. :)

<comment><USER5> and if possible without using Flash (maybe it could be done with canvas)

</comment></comment><comment><USER3> Nice that you can have your own Gitorious. But Gitorious is not Github. One of the biggest and most useful differences is the fork queue.

<comment><USER6> That's not the advantage of Github. The advantage of Github is that everyone else has an account already.

Account management is tedious, and it's something I never want to do. With Github, people can fork my projects without me doing anything until they actually commit something. This saves me a lot of time, since people _say_ they want to work on something, but never do. With Github, these people don't take up any of my time. If they do end up contributing it takes about the same amount of time to make them a committer on Github as it does anywhere else.

Anyway, the network effect always wins.

</comment></comment><comment><USER7> Call me a naysayer, but this is the danger of starting your company too close to the open source flame. Eventually the community decides they'd rather have an open/free version and you get burned.

<comment><USER8> on the other hand, the proprietary solution lasts only as long as the company providing it stays in business.

</comment></comment><comment><USER9> At first glance the name is unfortunately similar to "clitoris" - wonder if this deliberate?

<comment><USER10> yeah... *registers <http://gitoris.com>. I wonder if it gets type in traffic?

Seriously tho, don't down mod me I have a serious comment - IMHO, Github is way better just because of the graphics. I know, the old mac vs PC vs Linux debate comes to mind, but seriously graphics make me work better. They makes me happier. And Github is just pretty - the spacing of the letters are nice, the look is all light and pretty, etc. It makes me WANT to submit another commit!

But it's still awesome there are alternatives out there. Way to go, coder gents.</comment></comment>


Vast improvements seen by newest Oculus prototype - <AUTHOR> http://www.wired.co.uk/news/archive/2014-09/23/oculus-consumer-vr

<comment><USER2> This project keeps getting better and better every time they release an update. Can't wait to see how it works!</comment>


FAA Needs a More Comprehensive Approach to Address Cybersecurity - <AUTHOR> http://www.gao.gov/products/GAO-15-370

<comment><USER2> This GAO report is interesting. Some dopes in the popular press picked up on it saying "passenger wifi is linked to airplane control", because vague mention of that was made in the abstract. But, of course, the report isn't about that at all.

But it's more interesting in its recommendation that the FAA develop a holistic "agency-wide threat model" for its NextGen IP-based air traffic control system.

Haven't we outgrown the idea that the developers of large-scale systems should also be responsible for testing it? Haven't we understood, for a long time now, that developers have blind spots about their own work?

The danger of blind spots is only amplified by large bureaucratic organizations spending tons of money. If the FAA has "a" threat model, won't potential threats lying outside that model get ignored?

Public safety might better served be by a bug-bounty system, or by retaining several teams of outsiders to penetration-test a system like this.

But it will take some serious organization discipline to pull this off. Every software developer knows there's a twinge of embarrassment when the QA test finds a defect. Hopefully the NextGen team will be similarly embarrassed by the most ingenious of their pen-testing teams. And hopefully their organization will have the good sense not to punish them.</comment>


Context Free - a program that generates images from written instructions - <AUTHOR> http://www.contextfreeart.org/

<comment><USER2> This is an interesting program.

However, I found the headline a little bit misleading--I thought "written instructions" meant natural language. On the website, the blurb actually continues "...written instructions called a grammar" which makes it clear this doesn't expect natural language.

<comment><USER3> Interestingly enough, I actually know of a website which does exactly what you are talking about: <http://wordseye.com/>

(Full disclosure: I might potentially be working on a speech interface for this system soon)

<comment><USER2> Wow, that's really neat. I'll have to play around with it later.

</comment></comment></comment><comment><USER4> Nice idea, but not very revolutionary. I mean, we already have Processing, which is the same but with time included, and which has significantly more interesting efforts in its gallery, if you ask me. I'm not sure what these people are trying to achieve - if it's to get more people into procedural graphics, an (even) more accessible set of tools would be warranted. If it's to create splendid graphics, better tools would probably be warranted (though admittedly I've only checked 10 pictures or so).

On the programming-a-picture front: I always thought that this one [1] is particularly impressive (4 kilobyte Windows executable; zip includes a jpg for if you don't run Windows)

[1][<http://loonies.dk/demos/bin/lns-burjbabil.zip>]

<comment><USER5> The difference is that this language is rule based.

</comment></comment><comment><USER6> Another open source program in the same space: Structure Synth. <http://structuresynth.sourceforge.net/> (Combined with Sunflow to render can make some great images.)

</comment><comment><USER7> Reminds me of Forth Haikus: <http://forthsalon.appspot.com/>

</comment><comment><USER8> Almost like Logo (-;</comment>


What Democracy?: The case for abolishing the United States Senate - <AUTHOR> http://harpers.org/archive/2004/05/what-democracy-the-case-for-abolishing-the-united-states-senate/ <comment><USER2> _The answer is that democracy is itself a protection against tyranny, whether by the one (autocracy) or by the few (oligarchy)._

Except it's not, which is explicitly the reason for the Senate. It is there to slow things down - by design. Democracies have a pretty bad track record for turning into oligarchies.

Of late there has been much discussion about the reforming of the American governmental system because of it's "dysfunction." As a result there are a whole lot of Baby out with the bathwater approaches which are offered up as solutions. This article does the same and wishes away most of the problems that the idealization of the Senate is there to solve.

The article's main complaint seems to be that the "aristocracy" of the Senate maintains the power imbalance of the United States, which absolves the electorate of any responsibility. In fact the article never discusses anything beyond _the fact that_ the system is corrupted and that it is racially skewed. Never as to why, or describing some underlying mechanism that is keeping it there.

In the end, unless you think voting is "rigged" or somehow a sham, the responsibility falls on the electorate to manage who sits in the seats of power. Widespread apathy and disengagement (for often practical and legitimate reasons) keeps the same people in power and ensures that the wrong decisions and power will continue to be consolidated into too few hands.

Good example here: [http://www.thedailyshow.com/watch/mon- november-11-2013/not-s...](http://www.thedailyshow.com/watch/mon- november-11-2013/not-so-angry-voters)

</comment><comment><USER3> Originally the Senate was not elected by the people directly as democracy, but selected by their states as a republic. Direct election of Senators required a Constitutional a amendment.

Don't abolish the Senate, abolish the amendment that screwed it up.

<comment><USER4> It didn't screw it up. Sentatorial elections (and state govts in general) were horribly corrupt.

<comment><USER5> It screwed up the balance and if state governments are "corrupt" then it is up to the citizens of that state to fix it.

Given the ability to travel, my dream amendment would be to have the sitting governor of each state be that states single senator. That would stop some of the budget busting stupidity of Senators who have never done a budget.

<comment><USER4> > then it is up to the citizens of that state to fix it.

They did, they made them directly elected, and a considerable chunk of the state corruption died down

[http://en.wikipedia.org/wiki/Seventeenth_Amendment_to_the_Un...](http://en.wikipedia.org/wiki/Seventeenth_Amendment_to_the_United_States_Constitution) is a fine issue

<comment><USER5> That wasn't a fix since the Senators are no longer beholden to the states so they don't consider budgets. Look at the debt and bills that negatively impact states. It just moved the corruption and added lobbying in DC.

</comment></comment></comment></comment></comment><comment><USER6> Ok, can we at least acknowledge that _this_ article is completely off topic and has no business being discussed on a news site for computer programmers.

specifically: _Off-Topic: Most stories about politics, or crime, or sports, unless they 're evidence of some interesting new phenomenon._

This is:

        A) About politics and politics alone.
        B) Not in any way a new phenomenon.

<comment><USER7> I thought politics was taken to usually refer to what the government is doing. This is more about how the government should be shaped.

</comment></comment><comment><USER5> Given the Speaker of the Houses we have had over the years, I shudder to think what would have happened without the states interests being protected by the Senate. In fact, making Senators directly elected has been problematic for state budgets and allowed an overreach in DC that is not proper.

</comment><comment><USER7> If we're trying to find a better government, wouldn't it be better to decouple things? Break down the responisbilities of government into a few major areas that probably align fairly well to the existing structure (DoD, NIST, IRS & the social safety net programs, etc), and then instead of electing representatives and senators who get put on committees by seniority, elect people specifically to small-ish committees responsible for policy in one specific area.

</comment><comment><USER8> IMO, DC not having a vote is a far larger issue. The senate may not be 1 man 1 vote but DC has hundreds of thousands of people with no say in federal laws / taxes and rather limited self rule.

<comment><USER9> DC doesn't warrant being a state. Just like Virginia getting back it's land from DC in the mid 1800s, Maryland ought to get back the land it gave minus the mall area, SCOTUS, white house and capital.</comment></comment>


Ask HN: classic literature recommendations? - <AUTHOR>

Any suggestions on "classic" literature? I'm not too strict on the definition; I'm reading Kafka now and would probably consider it classic. <comment><USER3> Somebody posted "100 greatest books of all time" to HN just a day or two ago: <http://en.wikipedia.org/wiki/The_100_Best_Books_of_All_Time>

From that list I would personally recommend a number of titles, but I would also run away screaming from a few. Can you give more information about what interests you? For example, with Kafka, are you reading the shorter stuff, or "The Trial"? Do you like it or not? What are you looking for?

By the way, if you find something on there you like, then go give an upvote to ekm2: <http://news.ycombinator.com/item?id=4955541>

From that list, I would recommend the following to anybody: (Achebe - <USER2> Fall Apart), (Austin - Pride and Prejudice), (Laxness - Independent People), (Marquez - Love in the Time of Cholera), (Gogol - Dead Souls [translation by MacAndrew is the most fun one I've read]), (Twain - Huck Finn).

From that list, I would recommend the following only if I knew the person's tastes better: (Cervantes - Don Quixote), (Dostoevsky - The Idiot), (Kafka - The Trial), (Orwell - 1984), (Rushdie - Midnight's Children)

There are many other books I love that aren't on that list, but whether they would float your boat is anybody's guess. Personally I would read a shopping list written by Per Olov Enquist, but he seems to be an acquired taste, because nobody else I know digs him as much as I do (and only his "Royal Physician's Visit" seems likely to achieve "classic" status).

If you only know "The Three Musketeers" (Dumas) from movies, then you don't know them at all; the book is, for me, central to the idea of reading. If you liked "The Three Musketeers" then you might also like "Kidnapped" (Stevenson) and "Watership Down" (Adams)-- although probably few would consider that a classic.

"Catch-22" (Heller), "Mother Night" and "Slaughterhouse Five" (Vonnegut), and "The Little Prince" (Exupery) are all "classic" books I've read many times over. I was not a huge fan of "Les Miserables" (Hugo) before I read it out loud with my wife about a year ago, and it really grew on me then. To Orwell's "1984" I would add "Animal Farm". "My Antonia" (Cather) has something great in it, though many probably would consider it slow. "To Kill a Mockingbird" (Lee) deserves a call-out on any list of classics, especially if you're American. If you like Mark Twain, and want to read something really different by him, then have a look at "Joan of Arc."

<comment><USER4> If you enjoy Mark Twain, you might want to take a look at his lesser works and short stories. Some of them are quite good. [http://www.amazon.com/gp/product/1420931210/ref=as_li_ss_tl?...](http://www.amazon.com/gp/product/1420931210/ref=as_li_ss_tl?ie=UTF8&tag=caw02-20&linkCode=as2&camp=1789&creative=390957&creativeASIN=1420931210)

I remember "The Notorious Jumping Frog of Calaveras County" and "The Million Pound Bank Note" in particular, though it's been a few years since I read them.

</comment></comment><comment><USER5> Looking at my GoodReads favorites that qualify as classics, these are the ones that I enjoyed the most:

      - Anything by Jack London
      - Anything by Ernest Hemingway
      - *One Day in the Life of Ivan Denisovich* by Solzhenitsyn
      - *The Fixer* by Barnard Malamud
      - *Northwest Passage* by Kenneth Roberts
      - *To Kill a Mockingbird* by Harper Lee
      - Anything by Nikolai Gogol
      - Short stories by Guy de Maupassant
      - Most of John Steinbeck's works
      - *Lord of the Flies* by William Golding
      - *The Great Gatsby* F. Scott Fitzgerald

Also, if you're reading Kafka, _In the Penal Colony_ is a short story I enjoyed that I don't see mentioned much.

</comment><comment><USER6> Any list will vary some. You'll do well to read and listen to the works in this list: <http://home.comcast.net/~antaylor1/greatbooksstjohns.htm>

If you have the time and the interest I recommend learning Greek and Latin and reading the books in their original languages.

</comment><comment><USER7> I would highly recommend a subscription to Lapham's Quarterly if you want to get a wide taste of the "classic" cannon. Essentially, it is a collection of writings and art revolving around an overarching theme (The last two issues, for example, were "Politics" and "Intoxication"). The content includes fiction, poetry, letters, journal entries, biographies et al. It is all very high-quality stuff and I've been using it as a proxy for what to read next i.e. I'll read a really great excerpt and then I'll order the whole book on Amazon.

</comment><comment><USER8> Oh, it has to be Crime and Punishment (Fyodor Dostoyevsky). Blew me away. <http://www.gutenberg.org/ebooks/2554>

For lighter reading, The Adventures of Sherlock Holmes (Sir Arthur Conan Doyle). <http://www.gutenberg.org/ebooks/1661>

</comment><comment><USER9> _Brave New World_ by Aldous Huxley and _1984_ by George Orwell lay out two different visions of dystopian futures, if you're into that.

 _Candide_ by Voltaire is a classic satirical novel that still works fairly well imo, though it can be a bit un-subtle by the standards of modern literary satire.

</comment><comment><USER10> "Zen and the art of motorcycle maintenance" by Robert M. Pirsig. I read it this summer (as well as Der Prozess by Kafka, also recommended!) and I was constantly re-reading sections, finding new insights. The book really changed the way I look at some things in life.

</comment><comment><USER11> The Open Boat, by Stephen Crane. Ecclesiastes. Siddhartha, by Herman Hesse. All would be considered "classics", all have much to recommend them, and none is so long that you'd lose interest.

</comment><comment><USER12> Pretty much everything in the Penguin (Modern) Classics series.</comment>


Why does Microsoft own 7-Eleven? - <AUTHOR> http://en.wikipedia.org/wiki/7-Eleven

<comment><USER2> It was just added recently.. pretty sure its bs

<comment><AUTHOR> Yep.

</comment></comment><comment><USER3> Totally surprised until I heard Steve Ballmer Yell "Where's My Slurpee!!!!!!" to one of his assistants.

</comment><comment><USER4> The string 'micr' does not appear in the article. What are you blithering about.

</comment><comment><AUTHOR> I am just wondering how this never shows up in any discussions (public or private) pertaining to Microsoft when the Wikipedia clearly states that 7-Eleven pulls in over 80 billion in revenue a year.

I mean how come we have not seen Microsoft try to merge/scheme using the 7-Eleven brand with other products or services they offer? Maybe they do and I just never noticed.</comment>


Ask HN: Linux for tablets? - <AUTHOR>

Hello HN<p>I've been out of the game for a while, what is "the"   linux tablet distro nowadays? I used Jolicloud once, are there any better options? Thanks <comment><USER2> By Linux do you mean Linux kernel+Gnome/KDE/Xfce or do you mean Linux kernel only (Android/WebOS on top)?

If the former, and you want touchscreen, you're pretty much out of luck. Sorry.

<comment><USER3> "If the former, and you want touchscreen, you're pretty much out of luck. Sorry."

Not really. I have a SmartQ V7 tablet that triple boots Android, Linux, and Windows CE. They exist but generally aren't great. The V7 has a resistive touchscreen and is a bit old at this stage but does web browsing and HD video fine. I also got Debian up and running on it.

<comment><USER2> Interesting. How often do you use Linux on it? Are there many touch screen applications? How do you find them?

</comment></comment></comment><comment><USER4> I'd guess Android is the most well known one but that depends on what you consider 'linux'.

I think the difference between tablets and desktops is such that the underlying distro probably doesn't matter that much, it's more down to the frontend (I.E. Gnome looks pretty much the same whatever distro you run it on). I assume Gnome3 would run pretty well on a tablet although it's probably down to personal opinion

<comment><AUTHOR> In 'linux' i mean Linux. :) Not Android as it's ARM only. (Tried the X86 port, not working on my Acer W500)

Guess your right about the GUI. I'll try out some different DE's then. Thanks.

<comment><USER5> Oh, so you mean which GNU/Linux distro is suited best? Not which OS that uses Linux, the kernel...

<comment><AUTHOR> Yes, sorry

</comment></comment></comment></comment><comment><USER6> I have used Ubuntu on this HP TouchSmart TM2 flippy-screen tablet PC since I bought it. Touchscreen, stylus, basically everything works.

<comment><USER6> And I DONT use unity---just "Gnome Classic"</comment></comment>


Bioconservatives vs. Bioprogressives  - <AUTHOR> http://reason.com/archives/2012/02/17/bioconservatives-vs-bioprogressives/singlepage <comment><USER2> So I'm guessing that "Bioconservatives" are those in "opposition to the technologies that make life longer, healthier, and happier"?

Go, go Bioprogressives!</comment>


Python Qt tutorial: Create a (working!) chat client - <AUTHOR> https://build-system.fman.io/python-qt-tutorial <comment><USER2> Can I make all three platforms installers on Linux or do I need Windows and macOSX for the specific installers?

<comment><AUTHOR> You need Windows and MacOS.</comment></comment>


SmartAsset, the Financial Calculator Killer - <AUTHOR> http://blog.smartasset.com/news/2012/07/smartasset-the-financial-calculator-killer/#.UA7_mmGXSuI <comment><USER2> I just bought a house. We closed last Thursday and are moving in on Saturday.

I can tell you it's so true that it's really hard to figure out what's going on. Everybody will tell you different things, different banks and even friends and family.

I couldn't stand it, so I sat down and researched the mortgage calculator formula. It's actually pretty easy:

<http://www.hughchou.org/calc/formula.html>

I implemented this in javascript and was able to see my monthly payments and project my loan amounts over the years. This gave me a great way to fiddle with lots of parameters and instantly see differences. I was able to graph the results and see exactly where I broke even on different investments, etc, and completely decide, without persuasion, what kind of loan I wanted.

Most loan calculators suck. They don't really let you play around with the parameters, or they aren't clear on what they are including.

I'm happy to see this company because I'm all for opening up this kind of "fiddling" to people who can't program. I feel bad for people who are confused but don't have the skills to sit down and really figure it out. I wish you luck and I hope you better people lives with this.

EDIT: I played around with your tool a little bit. Here's where I think you guys should go: financial advice. Don't force people to tell you what down payment they need. If they don't enter one, suggest a few different amounts and show the difference it makes. If they don't specify a 15 or 30 year loan, show them the differences (pros and cons) and let them decide. In some cases, _persuade people to make good financial decisions_. You should rarely get a loan without any down payment. Tell people that.

<comment><AUTHOR> this is an amazing validation of the pain point. sounds like you and I had similar experiences. we want to get to the point where people do not need to do this themselves.

<comment><USER2> In some ways, I'd recommend restructuring the app a little bit and start low- level and allow the user to do his own research and build up his info.

For example, let the user put it the price of a house. That's it. With 0% down payment. Show them the graphs and the monthly payment (without taxes/insurance). In 1 second, they immediately have something in front of them.

Then, let them enter in a down payment, as they are doing so in real-time update the graphs/payments.

Then they choose 15 or 30 year, and keep adjusting parameters. They started simple but are slowly building up to see what makes a difference and aligning it with what they can afford.

At least, that's how I approached it. I want to see graphs/payment before I even have to tell you my savings.

</comment></comment></comment><comment><USER3> This is a tool for analyzing the _financing_ of the purchase. But half of the U.S. is underwater because they got the _pricing_ wrong.

Let's pass on housing bubbles for a second. Brokerage fees are the priceyist piece of the average housing purchase, something like 6% or so. But it seems that here these get rolled into the asset cost, the fees mentioned here are the financing fees.

Now we can say, "Yeah, that is another wrinkle and we have to fix that." But it's wrinkles all the way down. These decisions are complex because there are so many options.

Which goes to the key sentence in the post: "One place, where you can answer all of your questions, address all of your concerns and remove the anxiety created by unfamiliar jargon and complex financial consequences." This as plausible as one place to answer all your web development questions without all that technical jargon.

Mortgage finance is complicated because there are lots of options. The jargon represents those concepts. Grok the jargon, grok the concept, you're starting to get it. Want to understand without all that nasty jargon? Look, 99% of technical and financial writing could be more clear, and definitions and motivation of the jargon are generally lousy. But the jargon is there for a reason. I find claims to clarify jargon a lot more credible than claims to obviate it.

If the idea is to help some one get to a smart decision about a fixed or floating loan, without them actually understanding the difference and the implications and the various risks, I don't see it. You might be getting them into a better spot. But if they don't understand what they've done, they haven't made a financial decision, they've made a management decision about who they are going to trust. But that is essentially the same model as that of every calculator provider.

<comment><USER4> @chernevik -- thanks for the comments. W.r.t. the 6% "cost of sale" that is actually baked into the numbers. Granted it is fixed at 6% and cannot be changed (something we will allow shortly).

Please also understand that we've only just taken the first steps on this product. There are several more questions to be answered, and more interactive pages explaining the jargon, allowing users to visualize the variables that go into various (complex) decisions.

We also know that what we've embarked on is not something simple: answering complex financial questions, and personalizing them to an individual's needs is no trivial task.

However, we think we can build this out. What we released today is just the tip of the iceberg... plenty more to come shortly.

Hope this helps. And as always, if you have any comments or suggestions feel free to get in touch with us (firstname.lastname@example.com) any time.

Thanks!

<comment><USER5> Very nice and easy to use. One nice thing would be to be able to have:

\- the ability to change some of the assumptions, for example, 2% return on the savings is not what I have in my records for the past 10 years.

\- a small pie/stacked graph with where the money is going each month. 25% for mortgage, 25% for expenses, xx% for taxes, etc. This would provide a "fast check" for visual people.

I would love to have such tool for the German market :)

</comment></comment></comment><comment><USER6> This is certainly an area that needs clarity badly. Banks are clearly not disinterested parties when it comes to Financial Calculators (just like your Financial Advisor's Retirement Calculator is biased toward products they can sell you)

Once you nail this one, you should do the same for owning 'working' assets. Which is to say what sort of rate of return could one get on their money if they created an LLC, bought a property, and rented it out. All the same things go into the equation but the variables are subtly different (what mortgages can an LLC get that an individual can't? How about the other way round? Etc.)

<comment><USER7> That would be pretty cool. However, that seems like it would be getting into the commercial lending territory which would make it pretty difficult to pull off.

</comment></comment><comment><USER8> So: I used your thingy as soon as I saw the TC announcement, and while I believe you when you say that there's substantial modeling happening behind the scenes, I didn't perceive any of that. My end-user experience with your offering was of a very, very usable... financial calculator.

One thing that might have sold me on what you're doing behind-the-scenes: if there was a "dumb calculator" result you could have compared your numbers to in the results screen.

(Apologies if I missed you doing exactly that).

<comment><AUTHOR> thanks for the feedback. we've been trying really hard to simplify the application as much as possible. however it looks like there is an 'advanced' group of users that wants a lot more detail (which we have a-plenty). we have been thinking about letting people play with the raw models > is this something you would be interested in?

<comment><USER8> I want the opposite of punching more data into your tool; I'm just suggesting that if you're smarter than financial calculators, you show the user a naive calculator's predicted values alongside your own.

<comment><AUTHOR> thanks, you're not the first to raise that point. we'll give that some further thought.

</comment></comment></comment></comment><comment><USER9> I tried this out earlier today, and it's great but one thing confused me a little - your system seems to choose a home price for me based on income and savings. In the real estate market where I live this results in twice the house I would want/need. It also screws up the tax and rent/own calculations, I would think.

Is there some way I can set the max home price?

<comment><USER4> @brianmckenzie -- you can change the mortgage and/or downpayment on the home- affordability page (or any other page, clicking the "Edit" button in the Home Value box on the left sidebar). Feel free to ping us on Olark chat (on the site) if you have any issues.

Also, please do let us know why/where you think the tax and rent/own calculations are screwed up. thanks!

</comment></comment><comment><USER10> Curious to know your revenue model as you advance. Are you planning on 'referral fees' for presented loan offers? And would that approach threaten your appearance as source of neutral information?

I recently bought a house and used this[1] mortgage calculator, which was the best one I found. I liked how you can pivot from calculating on monthly income, purchase price, or a total monthly payment. An easy way to play with the numbers. Of course, since it's a simple calculator, it does require more manual input. I will say, though, it might be nice to have a manual mode with places you can input all those numbers a broker will throw at you.

[1] [http://www.mortgageloan.com/calculator/mortgage- qualifying-c...](http://www.mortgageloan.com/calculator/mortgage-qualifying- calculator)

<comment><AUTHOR> Thanks for attaching the link. We do generate referral fee from leads (we receive the same fee regardless of the lender so we maintain financial neutrality) but we're much more concerned with getting the user experience right (ie the second part of your note).

<comment><USER10> You guys are well on your way to getting the experience down and I certainly wish you existed when I was working through the purchase of my home. Excited to watch the product develop.

</comment></comment></comment><comment><USER11> A feature I'd love to see is should I refinance or not.

I've currently got a convoluted system of spreadsheets which I have to update every time I want to recheck against current rates. I'd basically like it to tell me in which scenarios it would make sense to refinance. I input things like amount of principle still outstanding, my current rate and term, how far I am into that loan, when I plan on selling, what the refi rate/term options are. The outputs I get are total cost (in fees and interest) by the prospective sale date, and total equity by the prospective sale date.

It is not necessarily in a lenders interest to give borrowers this information, since borrowers are trying to optimize based on paying the least amount possible.

<comment><AUTHOR> we're building out our refi functionality now. would be great to have you as a test user? we're going to have analysis and data not available anywhere else. info at smartasset dot com.

</comment></comment><comment><USER12> A bit of a quibble, but I don't like the "Done" button in the data-collection sidebar. I think "Submit," "Update," or "Save" would be better, but I can see where people don't like those words either. They'd seem to be a bit more on- point, though.

</comment><comment> alok-g See also: <http://michaelbluejay.com/house/> and <http://michaelbluejay.com/house/rentvsbuy.html>

</comment><comment><USER13> I put my information in, and the max home I can afford is about 1/5th the price of my current mortgage. I know that my house is more than I can afford, but that is a pretty large discrepancy.

<comment><AUTHOR> Hit us up on olark and we can go over your numbers.

</comment></comment><comment><USER14> My preference has been [http://www.nytimes.com/interactive/business/buy-rent- calcula...](http://www.nytimes.com/interactive/business/buy-rent- calculator.html)

There are a lot more options that I can take into account using the NYT version (ownership costs, HOA fees, specific mortgage rate, length of mortgage, rate of return of other investments, etc). How is this calculator better? Just because it's simpler?

</comment><comment><USER15> I wrote a very simple/basic calculator when I was shopping around for a home. FWIW, here it is: [http://krishna2.com/test/fastloancalc.fcgi?term=30&rate=...](http://krishna2.com/test/fastloancalc.fcgi?term=30&rate=4.5&amt=400000&yahoo_submit=Calculate&prop=&hoa=&down=&saved=&rfr=&taxb=&rent=)

</comment><comment><USER16> Scott Adams coined the term confusopoly to the business practise of making things so complex it is hard to work out what is really going on: <http://en.wiktionary.org/wiki/confusopoly>

This is a classic example along with cell phone carriers and retailers (try to work out special offers).

<comment><AUTHOR> thanks for that, confusopoly has a nice ring to it, and certainly fits.

</comment></comment><comment><USER17> > rely on the user for inputs most will not know (do you know your marginal > tax rate?)

Anyone who does not know their marginal tax rate has no business borrowing $100K's to buy a house.

The fact that such lack of financial knowledge is socially acceptable is a large contributing factor to the housing bubble; Buyers did not understand elementary finance.

</comment><comment><USER18> This interests me greatly cause I am trying to sell and then buy a house. The problem I see is that I can't tell your app that I don't want a down payment. I qualify for the VA loan which requires no down payment.

<comment><USER4> @varikin -- right now we don't source VA loans, however that is certainly on our near-term roadmap.

Also, the current product is limited to "first time home-buyers". Re- financing, buying a second home, and more are all coming very shortly.

<comment><USER18> Cool. I understand there is a lot of account for. Other than that gripe, this looks very cool.

<comment><USER4> Thanks!

</comment></comment></comment></comment><comment><USER19> FYI, here is the best rent v buy calculator I've seen thus far: <http://michaelbluejay.com/house/rentvsbuy.html>

</comment><comment><USER20> tl;dr This is a black box financial model driven by naive assumptions. Anyone can teach themselves how to recreate these calculations in Excel. The real value comes from helping people make better assumptions to drive the model instead of performing the calcs. Otherwise, it's just "garbage in, garbage out."

These calculations are a pretty black and white implementation of finance concepts taught in an introductory course. The most complicated math involves compounded growth and amortization. Granted, the data entry and presentation are well-laid out, but I could make a similarly easy to use Excel spreadsheet in 30 minutes with the ability to control all the model's drivers.

So I agree with others who have pointed out that you have made a very usable, albeit overly simple, financial calculator, but that's a fairly low barrier to entry product given the ease of the math and concepts.

As a real estate finance guy, I get asked for advice on home-buying all the time. The calculations are easy. The real value in my advice, or any financial advice for that matter, is help thinking through the assumptions that are used to power a financial model, not actually doing the math itself.

The drivers of your model are: 1) assumed comparable rent 2) home value appreciation 3) rental appreciation 4) financing (size, rate, amortization, and term) 5) annual expenses (I assume you inflate these at 2% too, but it's not listed) 6) and cost of capital (what you call "return on savings")

Right now, a majority of those variables are treated as an afterthought when they should be the main event. Therefore, I find the results of this calculator to be somewhat dubious. Said differently, I don't think this is going to help laypeople make better, more informed investment decisions because all you've got is a good-looking "garbage in, garbage out" financial model.

My suggestion is to guide people to make more informed assumptions that feed into your mechanical valuation tool. That would create real value. For example, challenge them to consider the determinants of appreciation. Will demand for the region in question outpace supply over the next 10 years? If so, appreciation will probably exceed inflation. Ask questions like these and based on the responses, convert them to quantitative inputs. [Admittedly, my question was probably too technical.]

Separately, your decision metric lacks objectivity. You present the "breakeven" point: the number of years that it would take for owning a home to be better than renting in gross dollars. Why not just ask upfront, "How many years do you expect to live in the same home?" and then give a definitive answer (e.g., "you should rent"). Even better, you could ask a number of questions to determine expected hold period. Age. "How long have you and your spouse lived in the region?" "How long have you and your spouse had the same job?" "Do you have family in the region?" "Is job mobility important to you?" Then convert these to a range of expected hold periods.

As you know, home buying is different from a typical investment in that it is a consumption good as much as it is a financial vehicle. There's plenty of emotion to contradict logic, if not more. If I find a house I _have_ to have, I'll make this model give me the conclusion I want it to give. That's what I mean by lacking objectivity. Worst case, I'll convince myself I'll stay in the region for 5, 12, 17 years, whatever your mechanical tool tells me.

My heuristic right now to friends and family: if you don't need mobility (job or otherwise), buy and borrow as much long-term debt as possible at these incredibly low rates. If inflation and interest rates spike, you'll make out really well. If inflation and interest rates stay where they are, you won't be much worse off. If you need job mobility, rent.

<comment><USER21> > If inflation and interest rates spike, you'll make out really well.

Will you explain this further?

As I see it - if interest rates spike (and incomes stay the some), buyers will be able to borrow _less_ , not more money at constant monthly payments. So housing values should go down? What am I missing?

<comment><USER22> OP referred to "long-term debt", so I think the point is that if interest rates spike then those with fixed interest rate loans are not affected and therefore able to continue with cheap long-term debt.

</comment></comment></comment><comment><USER23> This definitely solves a major paint point for a lot of people. Cheers and good luck. Great post!

</comment><comment><USER24> This is very cool. How do you plan to make money?

</comment><comment><USER25> "Just so you know we are not cherry picking this is the highest rank Google return for home affordability."

This is by definition cherry picking. The highest rank Google return doesn't say very much about the quality of the tool. It would be better (at least more honest) to simply show the best tools out there and compare your solution to theirs.

<comment><USER26> This is one of the best out of the rest.

<comment><USER27> You know this how?</comment></comment></comment>


Rubber Duck Debugging - <AUTHOR> https://fizentech.com/rubber-duck-debugging/ <comment><AUTHOR> How can you more effectively collaborate with others while working from home?</comment>


Memory Efficient String Compression in C# - <AUTHOR> http://blog.barvinograd.com/2012/11/memory-efficient-string-compression/

<comment><USER2> This seems like a lot of unsafe work just to avoid a temporary copy of the string's byte encoding. Isn't the garbage collector tuned for exactly that sort of short-lived data?

<comment><AUTHOR> You are right, it would go into the first generation and will be collected pretty quickly unless it is more than 85KB which many strings that you want to compress are. If you go into that string length you get into the Large Object Heap and that is a disaster. Unsafe work should not be scary. If you check out the code of GetByteCount for UTF8 encoding (as an example) you will see that Microsoft did the same thing.

<comment><USER3> I think this article is great. However, I think you should spend a little more time (like your last comment) describing why this is important; make it obvious why people should appreciate your work. I, for one, wish I was better at memory management since I spend most of my time in managed C# (and other languages with memory management). For your next post, spend a little more time spelling out the details for why each step is important: what is gained by not copying _this_ memory? Compare the memory usage profile of the managed vs. unmanaged algorithms. Explain the constraints of the GC (and perhaps some history). Many people assume the GC will always do a better job at managing memory than they can, so explain the corner cases for when that's not true.

<comment><AUTHOR> tkelogg, I am realy happy you found the post interesting and informative. Sometimes one forget to explain things that may seem obvious and one thinks that the code speaks for itself when it doesn't. I'll keep your advice in mind when I'll write my next post. In the mean time I have edited the post and added some additional explanations. Thank You :)</comment></comment></comment></comment>


Do Free Services Have an Obligation to Users? Should We Regulate Them? - <AUTHOR> http://danshafer.posterous.com/do-free-services-have-an-obligation-to-users

<comment><USER2> There is no logic at all underlying this piece. It's just pure entitlement — "I want everything and I want it for free without sacrificing any quality and I'm blaming you if I don't get it."

At no point does he consider the obvious — that if something is so important, maybe you should just _pay for it_. He talks about getting the government involved to provide a "cushion," whatever that means. Like, really? You think a huge regulatory department essentially tracking the entire Internet would be free?

<comment><USER3> I guess you can see it as entitlement on the part of the consumer but I see a sense of entitlement here on the part of the publisher. And who said anything about not sacrificing quality? You're projecting your fears onto me, hardly a fair argument.

The logic here is simple. If you provide a service, you have a moral obligation to treat those who use it with some modicum of respect. You obviously see some gain in being in the business or you wouldn't be there.

To say that I don't "consider the obvious" assumes that I've managed to put into a short blog post all my thoughts on the subject, again hardly a fair observation. I agree that if you have information that is valuable, you should pay for its storage and use or have it backed up. But that is obviously not true of a huge percentage of Internet users.

I don't advocate regulation. I wonder out loud if that's a viable solution. There are other approaches, such as a non-profit escrow system of some sort.

I just don't think it's considerate or in one's own enlightened self-interest to behave as if users of your free service are entitled to expect nothing. That just feels like a dishonorable way to do business.

<comment><USER2> Perhaps I misread the emphasis because you put "Should we regulate them?" in the headline. It seemed like the point was that we should expect some cool free service a kid sets up over winter break to live up to the same standard we would normally apply to high-end corporate services in the same space.

I agree that people should treat their users with respect, but your post goes far beyond that. You even say that a service offering full data portability and plenty of warning to its users if it's unable to continue is not good enough. Like, what more can we reasonably offer? I'm offering you something valuable for free and being completely honest with you, but still I'm a jerk for not making a lifetime commitment? That isn't rational.

And to be honest: I guess you could say I feel a sense of entitlement as the person offering a free service. If I offer my girlfriend a massage, I feel entitled to not give everybody else on the planet a massage as well. If I bring donuts to work, I feel entitled to not bring an unlimited supply of donuts forever. Of course, people wouldn't normally call this "entitlement" — only on the Net do people feel like I'm being "entitled" if I won't work for them for free.

</comment></comment></comment><comment><USER4> Regulating free services would be insane. The cost to start a startup have been dropping, and this is a good thing since it facilitates more innovation with less risk. If free services had to follow cryptic regulations it would significantly stifle the growth potential of future startups.

<comment><USER3> No disagreement. See my earlier reply just above. I tossed that idea out to see if it would stimulate some thinking about a good way to address the issue.

</comment></comment><comment><USER5> This article reminds me of Virginia Postrel's book _The Future and its Enemies_. This guy is one of its enemies.

<comment><USER3> Fascinating. You judge me in my entirety as an enemy of the future just because I post a single message with which you disagree. You indicate by your response that you prefer tossing word-bombs and accusations around in ad hominem attacks rather than engaging in meaningful dialog.

<comment><USER5> I'm sorry you feel insulted; that was not my intention. I meant to _categorize_ you according to Postrel's framework. Nevertheless, I think your point is wrong and you should read the book for a clear explanation of exactly why.

</comment></comment></comment><comment><USER6> I don't want free services on the internet to be regulated. Optimally, free services would stop driving their users crazy. The second best from my standpoint would be if users valued stability enough to start paying for things on the internet.

Given that the internet loves free services, and rages when they break/become unfree, we're stuck with the usual deal in the US: it's all Wild West laize- faire fun times until you really screw the pooch. After 5-10 years of stifling regulation, you're then back to Wild West laize-faire fun times.

<comment><USER3> I do not advocate government regulation. I raise it as a possibility hoping others will offer better solutions. So far, nobody has.

It is clear that, as a matter of law, users of free services are not entitled to any expectation of treatment. It is also true that as a matter of courtesy and integrity that those who supply such free services have a better plan than "Screw you, I'm outta here" in mind for if/when things go in a different direction.

<comment><USER7> That's because there is no better alternative. Without regulation you're just asking providers of free services to spend their time and money on integrating with a non-profit or NGO-provided... what? Data vault? That would only help with preserving raw data, not the social network that's the actual valuable part of systems like Twitter.

Courtesy and integrity for free services which change direction involves giving people sufficient notice, if possible, and allowing people to export their data, if possible. That's all! Anything more is a ridiculous expectation.

Sometimes it's not possible. You might think that you're going to secure funding in time, and then you don't, and you don't have the money to pay Amazon this month and now your service is gone.

Do you think that people who start free services on the internet have an obligation to supply that service, even if it means they pay for it instead of paying their rent? Should the founders of FreeWebService have to live on the street so that you can keep your social network alive?

Of course, if there were an American-tax-payer-funded NGO which would support my free web service when I ran out of money, I would definitely make a lot more free web services. I think a lot of people outside of the US would. :oD

</comment></comment></comment><comment><USER8> Regulate free services = free services are nothing but downside for the service provider -> no more free services.

It's pretty simple logic. The cure is worse than the disease.

Though I wonder if I'm being played. This reads like a parody of the big government position. "I've been abused by the big bad _free internet photo services_ and I need daddy government to come save me!"? Anyone _actually_ this helpless without big daddy government coming to their rescue has bigger problems.

</comment><comment><USER9> Government regulation tends to take decisions away from those who pay the costs and get the benefits and are acutely aware of their own needs

It gives those decisions to those who know little and care even less. Then the lobbyists get involved.

<comment><USER3> That is a politically conservative perspective and I respect your right to hold it. I don't see government as inherently bad, evil or inefficient, let alone uncaring.

<comment><USER9> Human interaction should be voluntary and mutually beneficial. But I respect your right to think it should be governed by coercion.

</comment></comment></comment><comment><USER10> "Free" implies no exchange of value; a one way street.

It's difficult to have a thoughtful discussion based on a false premise ( _I'm assuming Ning -and any other free service- derives some benefit from its users_ ). That said, changing TOS to the extent it alienates customers is a sure-fire way to relegate yourself into obscurity.

</comment><comment><USER11> No.</comment>


Nubia: A SoTA evaluation metric for text generation - <AUTHOR> https://wl-research.github.io/blog/ <comment><USER2> Based on your paper, it seems you didn't compare to other model based evaluation method such as Frechet Embedding Distance (FED). I would certainly like to see correlation study between each model evaluation method.

<comment><AUTHOR> Thanks for your feedback, while we couldn't compare with all model-based methods out there, YiSi (August 2019) and BERTScore which was just presented at ICLR2020 this week (April 27th 2020) are very strong methods to compare against and reflect state-of-the-art. All comparisons are welcome!

</comment></comment><comment><USER3> What do you think about the train test discrepancy? ie. will practitioners have to fine-tune Nubia's models on their training dataset in order to evaluate on their test dataset?

<comment><AUTHOR> The aggregators in Nubia are pretrained to correlate with human judgement, so it should only be used for inference, but the idea is that you can use it as a loss function to optimize translation/image captioning/summarization. It's too big for that as is but thats what we're working towards.

<comment><USER4> I think the question here is more along the lines of "If now, I have ,say, radiology reports, do I use Nubia out of the box or do I need to make it read radiology reports and have a sense of what high quality radiology reports look like before using it?"

<comment><AUTHOR> oh I see thanks! will clarify.

</comment></comment></comment></comment><comment><USER4> Super cool! If all the components of this metric are models, thoughtful versioning and documenting it will be important. What are your thoughts on this ?

<comment><AUTHOR> This is actually something we struggled with, and why we released everything this way. There is something to say about why BLEU and ROUGE have stood the test of time, they are extremely simple to use and static. Hopefully we can bridge this gap.</comment></comment>


Why Apple Must Tell Its Story (Apple after Jobs) - <AUTHOR> http://adage.com/article?article_id=129926

<comment><USER2> "Marketer Needs to Lay Out Succession Plan"

To AdAge, Apple is a "marketer?" Do they not even have a word for a company that builds things?</comment>


Build Doom3 on MacOSX with XCode4 - <AUTHOR> http://fabiensanglard.net/doom3_macosx/index.php

<comment><USER2> Why not just get these changes upstream?

Also, instead of forking it on GitHub, he just reuploaded the whole thing again (<https://github.com/fabiensanglard/Doom3-for-MacOSX->) so that others cannot easily merge these changes. And neither in his repo nor in his post, there is a reference to the original repo (<https://github.com/TTimo/doom3.gpl>).

Also, on the original repo, there were already a few fixes for Xcode4 and there is also a pull request with further fixes (<https://github.com/TTimo/doom3.gpl/pull/13>). I haven't checked it myself but it might actually work already.

Btw., further development is probably going on here: <http://www.iodoom3.org/> (<http://news.ycombinator.com/item?id=3277150>) (<https://github.com/TimeDoctor/iodoom3>)

<comment><USER3> > _Also, instead of forking it on GitHub, he just reuploaded the whole thing > again_

He responded in his comments:

> _If not, the fork will remain buried as a Pull Request with no visibility at > all._

Which is loads of bullshit. By design git is decentralized so _upstream_ is a mere convention, where usually the closest to _upstream_ is either the original author's repository or the most active repository.

<comment><USER4> I was actually writing a blog post on this issue as we speak. GitHub's approach is broken to how they handle forks. It's a long post but I updated it to mention your comment here.

<http://zbowling.github.com/blog/2011/11/25/github/>

<comment><USER3> A fork is a mere 'git clone'. The brilliance and simplicity of SHA1s makes linking repos as trivial as a _git remote add_. I venture it would be quite costly to actively look at every commit of a new repo to match it with every other commit in every other github repo (unless they start maintaining a global index of all SHA1s->repos). So for now Github merely records that one cloned a repo, and I seriously won't blame them for that.

If the guy did things properly, although inconvenient we could just do that to merge back, but apparently what he did was rewrite or recreate history in some way, so that SHA1s changed so it's not even possible to _add remote_ [0]. I guess that even with no common ancestor SHA1s one could still use _rebase --onto_ to replay some part of his history.

Either way I can't tell because the repo is 404 now and I did not have a chance to browse it, let alone _clone_ it.

[0] <http://news.ycombinator.com/item?id=3277181>

PS: I like some of your ideas, like hiding forks that can be fast-forwarded (i.e they have no changes i.e their HEADs are members of the parent repo), and detecting that one has pushed a repo that is obviously a clone of another, although I'd rather have it be manual (like a message on the github's console saying "we detected that this repo could be a clone of that repo, do you want to mark it as a fork?")

</comment></comment></comment></comment><comment><USER5> As someone who isn't familiar with game development, could someone explain what exactly is and isn't free? What happens if I try to run the game without the Doom3 media?

How might one go about making their own media for the game? Does it even make sense to do so? How tightly coupled is the released source code to the media?

<comment><USER6> _could someone explain what exactly is and isn't free?_

The source to the game executable (rendering, script interpreter, physics, pathfinding) is free and released under GPL. The assets, however, such as scripts, textures, shaders are still under the original commercial license.

It is certainly possible to make your own media for the game; it will be a lot of work, but arguably less work than writing your own game engine AND making the assets. It makes sense because the Doom3 engine is very flexible and you can do a lot with it, some of which has already been done in the form of mods (as the SDK has been available for a long time).

<comment><USER5> Thanks.

So if I wanted, theoretically, to modify the mechanics of the game, how would I do that with "assets"? For example, if I wanted to add "magic" or something (like mana from diablo 2), and perhaps change the way "score" is calculated, is that part of an asset as well?

Do engines provide a DSL for making games? I guess that's my question. It seems like media assets only allow you to reskin Doom instead of making a new kind of game.

<comment><USER7> In iD games, there's a clean division between game-specific logic (which is usually in a separate DLL, haven't looked too closely at Doom3 yet), and framework/engine code.

On Quake 2, you could replace the DLL to switch between the regular game and capture the flag. An expansion with new mecanics could, theoretically, be done with only DLL code and new assets. You'd need to change the engine code only to add new kind of effects that it didn't support yet.

So yes, if you don't change any code, you'll only reskin Doom by creating new assets (it's usually called Total Conversion). If you want to add new game mechanics, you have to write some code.

</comment></comment></comment></comment><comment><USER8> PVS-Studio: analyzing Doom 3 code: <http://www.viva64.com/en/b/0120/>

</comment><comment><USER3> Does the Doom3 source code includes RoE? There's no Mac port of RoE so now it could be possible to port it.

<comment><USER9> The idtech4 source code release does not include any game data whatsoever (only the game engine source code), so the short answer to your question is "no".

<comment><USER10> The slightly longer and more correct answer is the source release contains the game engine source and the Doom 3 and RoE game DLL source. The Doom 3/RoE game data is still required.

</comment></comment></comment><comment><USER11> "brew install doom3" would be sweet.

<comment><USER12> No idea what brew is but be aware that the game media is not free.

<comment><USER13> <http://mxcl.github.com/homebrew/>

</comment></comment></comment><comment><USER14> Sorry to hijack, but has anyone been able to do similar for wolfenstein: enemy territory (on OS X Lion)?

</comment><comment><USER15> My main issue is that I don't see why he's using a Das Keyboard with the letters on the keys. Doesn't that defeat the point?

<comment><USER16> They sell one with letters on the keys. I think its called the professional model. I always thought the point of das keyboards was the tactile button presses...

<comment><USER15> I suppose. I always assumed the point was to be obnoxious - I know that's why my brother bought one.

</comment></comment></comment><comment><USER17> cool job!</comment>


Linear algebra tutorial in four pages - <AUTHOR> http://minireference.com/blog/linear-algebra-tutorial/ <comment><USER2> A few minor mistakes (perhaps just in my eyes), but overall pretty good.

The hardest part about teaching linear algebra is that nobody explains the big picture. I teach mathematics and computer science and regularly tutor linear algebra students, and I encounter students all the time who ask me "What are vectors good for? I thought all we cared about were matrices and doing RREF and stuff."

For this reason, I deemphasize computations and emphasize the connection between linear maps and matrices. It can be summed up as follows: if you fix a basis, every linear map is a matrix and every matrix is a linear map, and operations on functions (like composition, inversion, whatever) correspond to operations on the corresponding matrices.

It's definitely not an analogy or anything in "scare quotes" that would imply something different is going on behind the scenes. It's exactly the same thing.

Other questions usually left out of discussions about linear algebra (and these notes): what are orthogonal vectors good for? Why would we ever want a basis besides the standard basis in real Euclidean space? Is Euclidean space the only vector space out there? Do vectors have to be lists of numbers?

<comment><AUTHOR> > What are orthogonal vectors good for?

Any set of n linearly independent vectors B_a={\vec{a}_i}_{i=1..n} in a vector space can be used as a coordinate system, but the "computational cost" of finding the coordinates w.r.t. the basis B_a will be annoying. Each time you want to find the coordinate of a vector you have solve a system of linear equations.

A basis consisting of orthogonal vectors {\vec{e}_i}_{i=1..n} is way cooler because you can calculate the coefficients of any vector using the formula $v_i = (\vec{v} · \vec{e}_i)/||\vec{e}_i||²

Of course the best thing is to have an orthonormal basis B_s={\hat{e}_i}_{i=1..n}, so that the coefficients of a vector w.r.t B_s can be calculated simply v_i = \vec{v} · \hat{e}_i. A projection onto the \hat{e}_i subspace.

> Why would we ever want a basis besides the standard basis in real Euclidean > space?

Hmm... I'm thinking eigenbases? The operations of a matrix A for vectors expressed in terms of its eigenbasis is just a scaling, i.e. {B_e}_[A]_{B_e} = Q^{-1} {B_s}_[A]_{B_s} Q = diagonal matrix = Λ.

> Is Euclidean space the only vector space out there? > Do vectors have to be > lists of numbers?

Good point. If I bump this to 5-6 pages, I will try to include something about generalized vector spaces. Orthogonal polynomials could be a good one to cover.

<comment><USER3> Computer graphics is full of fun topics that answer these questions in accessible and visible/tangible ways!

Skeletal character rigging in particular motivates a nice understanding of orthonormal bases and why a basis other than the identity matrix is very useful.

Even simple 2d conversions between screen space & pixel space, for example, can be useful motivational examples- its the thing your web browser did to render what you're reading. :)

Not that anyone would want to cover those topics in a 4 page linear algebra primer, but maybe there is some inspiration there for ways to include pictures that explain, instead of more math notation... ;)

The last 2 questions there are interesting and worthwhile topics for the interested student, but I'd say, just my $0.02, don't ruin a good thing by stuffing too much into it...

</comment></comment></comment><comment><USER4> It's a little surprising, in a "no-bullshit" discussion of "theoretical and computational aspects of linear algebra," to see matrix inversion touted as the way to solve linear equations. The guide literally introduces the examples by saying "Dude, enough with the theory talk, let's see some calculations." Yet standard numerical practice avoids literal inversion, in favor of factorization methods.

E.g., _It is common practice to write the form A^{-1}b for economy of notation in mathematical formulas... The trouble is that a reader unfamiliar with numerical computation might assume that we actually compute A^{-1}... On most computers it is always more effective to calculate A^{-1}b by solving the linear system Ax = b using matrix factorization methods..._ (Dennis & Schnabel, "Numerical Methods for Unconstrained Optimization and Nonlinear Equations", section 3.2).

E.g., _As a final example we show how to avoid the pitfall of explicit inverse computation... The point of this example is to stress that when a matrix inverse is encountered in a formula, we must think in terms of solving equations rather than in terms of explicit inverse formation._ (Golub and Van Loan, "Matrix Computations", section 3.4.11).

<comment><USER5> Yes, one almost never inverts a matrix using a computer, and one _never_ inverts a matrix by hand. What does that teach you? I was pretty surprised to see trivialities like this in a four-page summary. But, unfortunately, this is just a poor summary. It also barely covers the spectral decomposition, and has no mention at all of the singular-value decomposition.

<comment><USER6> we do matrix inversion by hand in mathematics :D

</comment></comment></comment><comment><USER7> As someone with a math degree, I love this. However, I think the author over- estimates the familiarity of a typical high school student with mathematical notation:

> The only prerequisite for this tutorial is a basic understanding of high > school math concepts

I think fundamentally the material in these four pages is accessible to many high school graduates, but perhaps not in this concise rendering (which is awesome for me, but probably overwhelming for someone not familiar with set- theoretic notation, summation notation, etc.).

<comment><AUTHOR> You are right. I am totally trying to sneak in the \in and the \mathbb{R}'s in there to see if people will notice.

Previously I had \forall in there too, but went over and removed things. On the TODO list is to introduce the { obj | obj description } notation for defining sets (in this case vector spaces).

<comment><USER8> Well, I noticed! It stood out pretty clearly, I'd say.

I really don't think that the intended audience of this sort of ground-up summary is going to be comfortable with \mathbb{R}^{m\times n} notation all over the place. Yes, you explain what the notation means, but there's zero chance that a reader who didn't already know that notation will become fluent in it right away: they're going to be flipping back to the definition every time. That might be okay if you're trying to teach all of math, but a person reading "Linear Algebra in Four Pages" presumably neither wants nor needs that full skill set. (I'd say that {obj|obj description} notation would make the text even more opaque to novices, no matter how cleanly introduced.)

Why not just make a less precise reference to a table of "numbers" (which, as an added bonus, would leave the door open to complex matrices without having to start from scratch)?

</comment></comment></comment><comment><USER9> A little observation: You repeatedly use language that fails to distinguish definitions & properties vs. effective computational methods.

For example, in section G:

> To find the eigenvalue of a matrix we start from the eigenvalue equation > ....

Solving the resulting equation is one way of computing eigenvalues. But it might not be the one you want to use in some practical situation.

Just before that, in section F:

> The determinant of a matrix, ... serves to check if a matrix is invertible > or not.

It is true that a square matrix is invertible iff is has nonzero determinant. It certainly is _not_ true that, for a matrix of any size, computing the determinant is a good method for checking whether a matrix is invertible.

<comment><USER8> > Solving the resulting equation is one way of computing eigenvalues. But it > might not be the one you want to use in some practical situation.

Related fun fact: Solving the eigenvalue equation is (in general) _impossible_ in closed form for matrices 5x5 or larger, because there's no closed form solution to the quintic. So some other algorithm for finding eigenvectors and eigenvalues is often absolutely required in practice.

<comment><USER9> Well, that depends on whether you want the _exact_ eigenvalues.

</comment></comment></comment><comment><AUTHOR> Good luck to anyone who has a linear algebra exam coming up!

I also have a similar short tutorial for Newtonian mechanics here: [http://cnd.mcgill.ca/~ivan/miniref/mech_in_7_pages.pdf](http://cnd.mcgill.ca/~ivan/miniref/mech_in_7_pages.pdf)

<comment><USER10> LinAlg 2 coming up in two days. Its a fun course!

</comment></comment><comment><USER11> I really enjoyed the Gilbert Strang videos on linear algebra back when I was taking the course at McGill: [http://ocw.mit.edu/courses/mathematics/18-06-linear- algebra-...](http://ocw.mit.edu/courses/mathematics/18-06-linear-algebra- spring-2010/)

<comment><USER12> Yes, very entertaining and enlightening (even if you already know the subject). Love Strang's teaching style.

<comment><USER13> I agree, his lecture deriving the determinant from a few desirable properties is a classic in my mind.

</comment></comment></comment><comment><USER14> Just to throw this out there in the hope it is useful, I have been using this book as a review of linear algebra:

[http://linear.ups.edu/html/fcla.html](http://linear.ups.edu/html/fcla.html)

<comment><AUTHOR> +1

This book is awesome! The entire text is interspersed with collapsable examples and exercises.

</comment></comment><comment><USER15> Roger Horn is one of the best linear algebra and matrix guys around, and I was, by wide margins, the star student in his class, effortlessly.

For the notes, I found serious problems in just the first half of the first column on the first page.

F'get about the four pages.

If enough people want an outline in a few pages, then I'll consider knocking one out and putting up somewhere as a PDF file.

<comment><USER16> I'd be happy to see three serious problems described in the first column of the first page.

<comment><USER17> I'll take a crack at being as pedantic as possible. I'm just doing this to play along.

1) "Linear algebra is the math of vectors and matrices" \- I think this would be better phrased as "the math of vectors and linear transformations." Matrices are a convenient way to represent finite dimensional linear transformations, but I think it's putting the cart before the horse to say that linear algebra is the math of matrices. This is a minor problem, though.

2) "A vector ⃗v ∈ R^n is an array of n real numbers" \- In general vectors are not arrays of numbers, real or otherwise. This kind of definition will run into problems when you get into Hilbert/Banach spaces.

3) "the function f(x) = ln(x) has the inverse f^−1(x) = e^x" \- this is only true for x > 0 if we're talking about the real-valued logarithm function, since it's not defined for x <= 0.

<comment><USER16> Thank you, that is awesome. So are all the problems ones of a pedantic nature? For example I understood the inverse function description as a definition even though there was a range (which I also knew) for which it was invalid.

Generally I consider those sorts of things to be the difference between writing 'proofs' versus explaining concepts.

<comment><USER17> Yeah, I wouldn't really consider any of those things to be "serious" problems, at least for the level that this guide is pitched at.

</comment></comment></comment></comment></comment><comment><USER6> erk, I don't think condensing much information in the smallest place possible is the best way to learn something (or even review it).

I'm all for a no bullshit and quick way to get something. That's why I sometimes check learnXinYminutes.com or some random cheatsheets on Google. But this doesn't make it for me.

Btw, if you really want to get a good grasp on Linear Algebra you should check Gilbert Strang's video courses on MIT OpenCourseWare. They are amazing and soooo easy to understand you don't even need to like mathematics to watch them. I haven't come across a better support to start with Linear Algebra.

<comment><USER18> Course codes 18.06SC and 18.06 i think if anyone else was looking. Thanks for the pointer, really appreciated!

<comment><USER19> Got excited for a moment...then did some prerequisites digging and ended up with a prerequisites dependency chain:

18.06 -> 18.02 -> 18.01

Where 18.02 = Multi Variable Calc 18-01 = Single Variable Calc

Considering that my whole point of learning linear algebra was to clear it as a roadblock for Machine Learning, this is what my whole Dependency chain looks like:

Machine Learning -> Linear Algebra -> Multivariable Calc -> Single Variable Calc -> high school algebra and trigonometry.

I have a feeling I'll end up sticking to being a web developer :)

<comment><USER20> Calculus gets a bad rap for being difficult, but if you're learning on your own, you can just focus on the ideas and not on the arduous computation (which something like maxima can do for you). The core ideas of calculus can probably be learned in a week. Review all the trig on Khan Academy, then try watching some calculus lectures, focusing on the big ideas, not memorizing rules for computing derivatives or integrals.

BTW, you probably don't need much calculus to learn most of the linear algebra you need; those requirements are mostly there for mathematical maturity, plus then being able to assign more interesting exercises.

<comment><USER21> Gilbert Strang made a great series of lectures on the big ideas of calculus sans most of the computation - [http://www.youtube.com/playlist?list=PLBE9407EA64E2C318](http://www.youtube.com/playlist?list=PLBE9407EA64E2C318)

</comment></comment></comment></comment></comment><comment><USER22> Why do linear algebra teaching materials never mention what a determinant _is_?

(It's the product of the eigenvalues.)

<comment><USER23> > _It 's the product of the eigenvalues._

It sure is (provided you count multiplicities correctly), but that's not the one-sentence explanation I would have gone with, even to someone with much more intuition about eigenvalues than you'd get from this document. I would say the determinant is the volume scale factor (or hypervolume scale factor, in the general case).

Actually, what's really interesting to me is your general point: why do _< teaching materials for mathematics subject X>_ never mention _< the key insights that made subject X clear to me>_? And why does this question not get asked more often? The nearest I've been able to come to a plausible answer is a mixture of (i) the key insight varies from person to person more than you'd think, combined with the closely related (ii) you can't teach key insights just by saying a few words.

<comment><AUTHOR> Thank you for your comment! First off the explanation regarding det(A) = the volume scaling of the transformation T_A associated with the matrix A. I've been stuck for over a week now trying to word this any other way possible because, in the current ordering of the sections, I'm covering determinants before linear transformations. Perhaps there is no better once sentence than talking about the volume and I should reorder the sections...

You've raised a very important point regarding "routes to concepts" which really should be asked more often!

> (ii) you can't teach key insights just by saying a few words.

Generally true, though we have to say that the key difficulty in communicating insights is lacking prerequisites. Therefore, if you think very carefully about the prerequisite structure (i.e. model of the reader's previous knowledge) you can do lot's of interesting stuff in very few words.

> (i) the key insight varies from person to person more than you'd think,

Let G=(V,E) where V is the set of math concepts, and E are the links between them. Then there are as many ways to click on a concept x, as there there are in-links for x! In this case we have at least three routes:

      Route 1: geometric
       lin. trans T_A = {matrix:A, B_in:{e1,..,en}, B_out:{f1,..,fn}}
       ---> what happens to a unit cube 1x1x1,
            represented  (1,...1) w.r.t. B_in,
            after going through T_A?
            ---> output will be (1,..,1) w.r.t. B_out
                 ---> observe that cols of A are f1..fn
                      therefore
                         det(A) = (hyper)volume of (hyper)parallelepiped
                                  formed by vectors f1..fn

       Route 2: computational
        det(A) = { formula for 2x2, formula for 3x3, ... }
        ---> a easy test for invertibility of an n by n matrix
        sidenote: see Cramer's rule for another application of dets

       Route 3: algebraic
        given a 2x2 matrix A,
        find a coefficients A T D that satisfy the following matrix equation:
             B*A^2  + T*A  + D   = 0,
        the linear term is the trace T = sum_i a_ii, the constant term is D = det(A).
        sidenote:  B*λ^2 + T*λ + D = {characteristic poly. of A} = det(A-λI)

So perhaps the task of teaching math is not so much to try to find "the right" or "the best" route to a concept, but to collect many explanations of routes (edges in G), then come up with a coherent narrative that covers as many edges as possible (while respecting the partial-sorted-order of prerequisites ).

</comment></comment></comment><comment><USER24> I love a lesson that doesn't include ANY real world examples. What's the purpose of this document? Does it accomplish that purpose?

<comment><AUTHOR> I'll have to add some examples, yes >> TODO.txt

purpose = to give a quick intro to the subject (the most important idea at least, namely, that matrix-vector product can represent linear transformations).

</comment></comment><comment><USER25> Suppose that you are driving a car and you are hit with a big tree. The main eigenvector is in the direction from the car to the tree, the eigenvalue measures the deformation of the car produced by this accident. If the car is a half shorter after the accident then the eigenvalue is 1/2.

</comment><comment><USER26> Wow amazing stuff here, I agree with you that most math textbooks in our education system fail to explain concepts which are supposed to be very simple. Thank you so much for making things simpler. I'm having MATH 270 final next week at McGill, this is going to help a lot in studying :)

</comment><comment><USER27> No pseudo-inverse, no singular value decomposition, no least squares regression, no k-nearest neighbors and I'm sure I'm leaving many other things, all fundamental algebra very much needed for understanding and developing of computer science (e.g. machine learning, data storage and compression), telecommunications (e.g. queueing theory, multimedia coding and streaming) and many other fields related to engineering. I lovehate maths (I really struggle with them), but I honestly think our linear algebra book back in grad school was 600 pages for a good reason, you just can't do proper engineering without it. (Also I have another really thick book on the most important numerical methods for implementing that algebra on a computer, so, come on! :-))

</comment><comment><USER28> This is really basic. Noone(who uses the subject) should need a cheat sheet for this... Also there are really good books out there and linalg is a must nowdays. As for textbook: [http://www.amazon.com/Linear-Algebra-Right- Undergraduate-Mat...](http://www.amazon.com/Linear-Algebra-Right- Undergraduate- Mathematics/dp/0387982582/ref=sr_1_1?ie=UTF8&qid=1386775556&sr=8-1&keywords=linear+algebra+done+right) As for reference: [http://www.amazon.com/Matrix-Analysis-Roger- Horn/dp/05213863...](http://www.amazon.com/Matrix-Analysis-Roger- Horn/dp/0521386322/ref=sr_1_3?s=books&ie=UTF8&qid=1386775486&sr=1-3&keywords=matrix)

</comment><comment><USER25> Suppose that you want to project a vector of data (x1,x2,x3,...,xn) into the one dimensional subspace generated by the vector (1,1,...,1). What's the projection in this case?

Hint: You obtain the most important concept of statistics.

</comment><comment><USER29> I wish I had this in grad school when I had forgotten all my undergrad Linear Algebra. It's not a very hard or deep aspect of math if you understand the fundamentals, so this is very useful.

</comment><comment><USER30> Courses would benefit from "quick-reference guides like the end of Dror Bar Natan's paper on Khovanov homology [http://arxiv.org/abs/math/0201043](http://arxiv.org/abs/math/0201043) He says "It can fit inside your wallet."

See: [http://www.math.toronto.edu/drorbn/Talks/HUJI-011104/cube.gi...](http://www.math.toronto.edu/drorbn/Talks/HUJI-011104/cube.gif)

</comment><comment><USER31> Very cool, I like title of the associated book "No Bullshit Guide To Linear Algebra" too.

Does anyone know of a nice, short summary of discrete mathematics to go along with this?

</comment><comment><USER32> Studying at a university where all this and more is part of the first year education of computer scientists, I - probably foolishly - assumed basic linear algebra was common knowledge in the community. Now my interest is piqued: Which educational path / career path did you take ending up in IT and (more specifically) how much mathematical education did it include?

What is your educational background and which route

</comment><comment><USER33> I bought this guy's previous book and the print quality was crap. I hope he improves this on his next book.

</comment><comment><USER25> In page 3, section B. Using elementary matrices: To remember what matrix correspond to a row operation just apply that operation to the identity matrix and you obtain the elementary associated matrix.

</comment><comment><USER34> Here is a 1914 book on calculus. Calculus made easy by Thompson Silvanus Philip

[http://www.gutenberg.org/ebooks/33283](http://www.gutenberg.org/ebooks/33283)

</comment><comment> nathan-wailes thanks for the post, i've been trying to learn linear algebra for a long time but keep getting stuck / bored.

<comment><USER11> For me what makes it really interesting is the realization that all of linear regression (think y = mx + b) is based on linear algebra, specifically the notion that figuring out a best-fit line (in the case of a single-dimensional input variable) is projection of the N-dimensional vector space of observations (where you have N data points) onto the best-fitting 2 dimensional vector spaces (assuming you're fitting a slope and an intercept).

When thought of this way, a lot of linear algebra has geometric interpretations and for me this makes it a lot less abstract.

<comment><AUTHOR> Yeah, dergachev is pointing to one of the cool direct applications of linear algebra to machine learning.

Suppose you are given the data D = (r_1; r_2; r_3) where each row r_i is an n-vector r_i=(a_i1, a_i2, ..., a_in, b_i). Each row consists of some observation data. We want to predict future b_j given the future \vec{a}_j, given that we have seen {r_i}_{i=1...N} (The data set consists of N data rows r_i where both \vec{a}_i and b_i are known).

One simple model for b_j given \vec{a}_i = \vec{a}_i = (a_i1, a_i2, ..., a_in) is a linear model with $n$ parameters m_1,m_2,...,m_n:

       y_m(x_1,...x_n) =  m_1x_1 + m_2x_2 + ... + m_nx^n  =  \vec{m} · \vec{x}

If the model is good then y_m(\vec{a}_i) approximates b_i well.

But startup wisdom dictates that we should measure everything!

Enter error term:

       e_i(\vec{m}) = |y_m(\vec{a}_i)   - b_i|²,

the squared absolute-value of the _difference_ between the model's prediction and the actual output---hence the name error term.

Our goal is to make the sum $S$ of all the error terms as small as possible.

       S(\vec{m}) = \sum_{i=1}^{i=M} e_i(\vec{m})

Note that the "total squared error" is a function of the model parameters \vec{m}.

At this point we have reached a level of complexity that becomes difficult to follow. Linear algebra to the rescue!

We can express the "vector prediction" of the model y_m in "one shot" in terms of the following matrix equation:

      A\vec{m} = \vec{b}

      where A is an N by n matrix  (contains the a_:: part of the data)
      \vec{m} is an n by 1 vector  (model parameters---the unknown)
      \vec{b} is an N by 1 vector  (contains the b_: part of the data)

To find \vec{m}, we must solve this matrix equation, however A is not a square matrix: A is a tall skinny matrix N >> n, so there is no A^{-1}.

Okay so we don't have a A^{-1} to throw at the equation A\vec{m}=\vec{b} to cancel the A, but what else could we throw at it. Let's throw A^T at it!

         A^T A \vec{m}  =  A^T \vec{b}
         \   /
           N   (an n by n matrix)

           N \vec{m}  = A^T \vec{b}

Now the thing to observe is that if N is invertible, then we can find \vec{m} using

            \vec{m}  = N^{-1} A^T \vec{b}

This solution to the problem is known as the "least squares fit" solution (i.e. choice of parameters for the model m_1, m_2, ..., m_n). This name comes from the fact that the vector \vec{m} is equal to the output of the following optimization problem

        \vec{m}   =  minimize S(\vec{m}) over all \vec{m}

Proof: [http://en.wikipedia.org/wiki/Linear_least_squares_(mathemati...](http://en.wikipedia.org/wiki/Linear_least_squares_\(mathematics\)#Derivation_directly_in_terms_of_matrices)

Technical detail: the matrix N=A^T*A is invertible if and only if the columns of A are linearly independent.

TL;DR. When you have to do a "linear regression" model of data matrix X and labels \vec{y}, the best (in the sense of least squared error) linear model is \vec{m} = (X^T X)^{-1} X^T \vec{y}.

<comment><USER35> That literally made more sense than anything I've learned this semester. :)

</comment></comment></comment></comment><comment><USER36> Does anyone have a recommendation for an equally good and concise guide for Discrete Mathematics by any chance?

</comment><comment><USER37> Literally just finished this exam. Too bad I didn't see this summary 4 hours ago!

</comment><comment><USER38> Linear algebra class in one abbreviation: LAPACK.</comment>


Show HN: Stockflags - free, realtime stock alerts - <AUTHOR> http://www.stockflags.org

<comment><USER2> If this is your website, then a bit of CC: That page is was too minimal. The only thing I know about your project is that it gives me free real time stock alerts. I don't know how it does so and I have no idea what your project is. Based on that, I'm highly unlikely to click sign up.</comment>


Ask HN: Why did GoDaddy support SOPA? - <AUTHOR>

I know they pulled their support to try to save face/business, but why did they support the legislation so publicly in the first place? In other words, what was their angle? They must have known it would cause some measure of backlash (though they probably didn't expect this much) but what do they as a company personally get out of SOPA, from a profit perspective? <comment><USER2> 1\. Seized domains might be a de-facto transfer to GoDaddy

2\. GoDaddy seems to be exempt from shutdowns under SOPA [1]. So this would mostly hurt their competition.

[1] <https://news.ycombinator.com/item?id=3387960>

<comment><AUTHOR> Did not realize they were exempt. That explains it.

</comment></comment><comment><USER3> It seems odd to me as well. They would be impacted by the legislation because as a domain registrar and DNS server, they'd have to invent and implement the technology to comply with SOPA (e.g., taking down a website).

You might think they have something to gain monetarily, but I'm having a hard time thinking of what that might be. They may take control of revoked/blocked domains, but those domains would have little to no value (since they are blocked) to resell.

The only thing I can think of is just that Bob Parsons or senior management agrees with it on a personal level and used the company name to back it up.

I do know that Go Daddy pretty aggressively defends it's own trademarks and copyright, but even that seems like a stretch to justify supporting it.

</comment><comment><USER4> They helped write it, and exempted themselves. Huge competitive advantage, while currying favor with Congress and media industry.

</comment><comment><USER5> $</comment>


Microsoft Is Backporting WSL2 to Their Windows 10 2019 Releases - <AUTHOR> https://www.phoronix.com/scan.php?page=news_item&px=Windows-10-WSL2-Backport <comment><AUTHOR> IMO something went horribly wrong somewhere for this to have to happen. Where I work we have some years old version of Windows 10 also that does not support some basic stuff. Really suboptimal outcome.</comment>


What Shakespeare Teaches Us About Living with Pandemics - <AUTHOR> https://www.nytimes.com/2020/03/28/opinion/coronavirus-shakespeare.html <comment><USER2> Plague erased social, gender and personal differences. Shakespeare responded by emphasizing people's unique and inerasable difference. His work is a narrative vaccine.</comment>


Styleguide Driven Development - <AUTHOR> http://webuild.envato.com/blog/styleguide-driven-development/

<comment><USER2> nice idea, but I would like to see some demo of this, e.g. with static page or a github repo. The relationship between UI elements/DOM and the "application presenter" is a bit far fetched for me, making the styleguide involve HTML, ERB, CSS, and some Rails app?</comment>


Let's Quit Fetishizing the Single-Family Home - <AUTHOR> https://www.nytimes.com/2020/02/05/opinion/california-single-family-housing.html <comment><USER2> 'cause you ain't gonna be able to afford it</comment>


Can Truth Prevail Online? - <AUTHOR> http://www.astickadogandaboxwithsomethinginit.com/2018/11/can-truth-prevail-online/ <comment><USER2> Basically politicians are mostly self serving liars, who use extremist media outlets to spread deception to gullible people who don't really understand anything more than opinions and the herd mentality.

Hence multi-millionaire celebrities endorsing things they would never in 100 years participate it. Celebrities getting busted for not paying taxes in the 10's of millions, but meanwhile they are trying to convince us that we need to pay more taxes and distribue our wealth.

I dont own 100 cars and a helicopter.</comment>


The Magnetar Trade: How One Hedge Fund Helped Keep the Bubble Going - <AUTHOR> http://www.propublica.org/feature/the-magnetar-trade-how-one-hedge-fund-helped-keep-the-housing-bubble-going

<comment><USER2> Magnetar says it was "market neutral," meaning it would make money whether housing rose or fell.

Sounds like they were acting as market makers to me. Taking up risky long positions and hedging with short positions to protect the downside. Sounds like whoever took the risk of the short position misjudged the cost of that risk.

</comment><comment><USER3> All I got out of the article was that a hedge fund was hedging.

<comment><USER4> This wasn't a normal hedge. They were actually creating the products that they were betting against.

<comment><USER5> In what way do you think that makes it an abnormal hedge?

<comment><USER6> It eliminates the legitimate justification for a hedge.

The argument behind hedging is that it's like taking out insurance: it allows you to take a position that you'd like to be in (invest in a home, for instance) but that you would otherwise find too risky.

What they were doing, essentially, was buying a house and insisting that it be built on an unstable foundation, in a tornado zone, with substandard wiring and a garage piled with oily rags, in the hope that it'll get destroyed and they can collect the insurance.

<comment><USER7> A hedge fund isn't supposed to hedge away all returns. The hedged part means that they buy and sell similar assets whose prices reveal discrepancies. In this case, there was a discrepancy between the return of the equity slice of CDOs (very high, implying a high default risk) and the cost of insuring the debt portions of CDOs (very low, implying a low default risk).

Magnetar basically said "Okay, the risk is probably not as high as the equity guys think. And not as low as the debt guys think. Why don't we buy from the equity-holding pessimists, sell to the debt-holding optimists, and pocket the difference?" And they bought, sold, and pocketed.

If you're going to be outraged, pick one:

Did they profit from the misery of others by selling short? Then they had to be net sellers, which decreased prices and made the bubble smaller. Or did they needlessly fuel a speculative bubble? In that case, they had to be net buyers, which would make them net losers.

Since Magnetar was long volatility (returns will either be way better or way worse than investors expect), this complicates things. But they basically made money from being right, while their counterparties lost money for being wrong. As long as everyone goes into these transactions with the same information, that's the only way fools and their money are parted.

<comment><USER6> The article asserts that Magnetar was net short on the CDOs, although the This American Life episode makes that more clear than the linked article does.

They can't prove that Magnetar was net short, because that information isn't pubically available. But their evidence was that Magentar was pressuring the banks who were creating the CDOs into building them out of unusually risky assets. They have emails from a deal that fell apart because the bank refused to bundle in the assets that Magnetar wanted.

> Did they profit from the misery of others by selling short? Then they had to > be net sellers, which decreased prices and made the bubble smaller. Or did > they needlessly fuel a speculative bubble? In that case, they had to be net > buyers, which would make them net losers.

The thing is, Magnetar was _only_ buying the equity position of the CDO. They were then buying insurance against the higher tranches failing.

They were sponsoring billion-dollar CDOs with a few million dollar investments in the lowest tranche. They were then buying insurance against the failure of the much larger upper tranches. Without them buying the equity, the CDO wouldn't have been created.

The argument is that without Magenatar, the CDOs wouldn't have come into existence (because they wouldn't have had a sponsor willing to buy the equity tranche). Magnetar wanted the CDO to fail as evidenced by its pressure of the banks to include rotten assets. So my analogy stands, they insisted on the construction of a dangerous house so they could collect the insurance.</comment></comment></comment></comment></comment></comment>


BMW's new electric car powertrain system totally torpedoes Tesla - <AUTHOR> https://www.wired.co.uk/article/bmw-electric-car-powertain-tesla <comment><USER2> These people are really funny. Especially the old german manufacturers are so so similar to Nokia's leadership. Tesla is not some kind of a new car. It is not even a car in consumer's perspective! It's a gadget. A very expensive gadget but still a gadget.

Tesla is what iPhone was to Nokia/Symbians. Tesla is so much ahead in the markets where it matters that the traditional car manufacturers should really be scared. They are good at making cars that's undeniable truth but are they good enough to produce gadgets ?

The car of tomorrow is the new iphone. The traditional middle class dudes are dying out, the ones that will be able to afford cars at this price point will rarely shop traditional cars with shitty infotainments and no ecosystem.

The reality is that the closest ones getting to a Tesla level will be the ones understanding the market. The chinese will surely get it right as they can do things on their domestic market others cant and the Koreans have Samsung that will help them out.

The rest of the world can only try but will slowly fade into irrelevance.

<comment><USER3> _> Especially the old german manufacturers are so so similar to Nokia's leadership_

no coincidence.

one of Nokia's major R&D sites is in Ulm Germany (well where Siemens used to be until the merger). BMW & Continental have created R&D sites around 3 mins walk from the Nokia offices and absorbed hundreds of ex Siemens (ex Nokia) staff during the time that Nokia merged with Siemens and laid off a lot of staff.

</comment></comment><comment><USER4> "The genius of BMW's new powertrain system is that the company is in effect backing every horse in the race."

So the new powertrain has gasoline engine in front, battery in the middle, and an electric motor in the back. The concept is interesting and would have been revolutionary 10 years ago. Back then it would accelerate fleet electrification. However with Tesla and other manufacturers introducing purely electric cars it feels like a cop out. They can't seriously be trying to spin that in a positive way.

"The production model of the BMW Vision iNext, due 2021" "The full EV iNext will have a range of 435 miles and support level three autonomy at up to 80 mph on motorways"

So it is coming in 2 years, with groundbreaking features available elsewhere now and a somewhat longer range that should be expected due to expected battery capacity increases.

</comment><comment><USER5> We will know it has torpedoed Tesla when headline writers no longer need to put "Telsa" in the headline to generate a click.

</comment><comment><USER6> Clickbait. How does it "totally" torpedo Tesla again? All I read was their new prod. line in 2021 can handle ICE/EV/Hybrid.

</comment><comment><USER7> I wonder how much BMW "paid" aka wined and dined that Wired writer. BMW has neat electrical cars but in comparison to literally every other manufacturer they are total turds. Seriously, I love the design of the i3 but 80 mile range out of the box is damn near useless. Being able to drop that drivetrain into your 3 series doesn't make a tesla killer.

<comment><USER6> Its an opinion piece but even failed to opine how this torpedos Tesla... in 2021.

</comment></comment><comment><USER8> Here's what torpedo damages look like: [https://cleantechnica.com/2018/12/08/tesla- model-3-completel...](https://cleantechnica.com/2018/12/08/tesla- model-3-completely-crushing-us-luxury-car-competition-10-cleantechnica- charts/)

</comment><comment><USER9> The vehicle has to have space for both an IC engine and a battery. Do they put a thick floor and a big engine compartment in every car?

<comment><USER6> I think it's meant to have only one. The _production line_ is adaptable to manufacturing either an ICE vehicle or an electric one or a hybrid.

</comment></comment><comment><USER10> Clickbait. TLDR; BMW is not ready to fully commit to electric.</comment>


Feedback on atfight.me signup page? - <AUTHOR> http://atfight.me

<comment><USER2> There's really not much to say, it's the same as all the others except for the background image.

"Feedback on my startup" is far more interesting than these landing pages.

</comment><comment><AUTHOR> Would love to get your feedback on our signup page!

<comment><USER3> Why do I need to sign up? What service are you providing? You don't give me _any_ hints and these types of tell me nothing sign up pages are getting old. Give me something! That's my gut reaction. I reached for the back button. Sorry if this comes off as harsh. This was my honest reaction.</comment></comment>


Ask HN: Anyone with experience running a software company as a 501(c) charity? - <AUTHOR> What is the organizational structure like?  Who can be paid? In your experience what are/were the benefits and drawbacks? Etc. <comment><USER2> Upvoting because I think that it's a good idea, but I don't know any of the details.</comment>