30thElement

To expand a little, most container ships use bunker crude, which is borderline sludge. It even needs to be heated before being pumped out. But it's cheap and at the size, pressure, and speeds these engines run at they get most of the energy out of just about any fuel.

Vim kinda has this. You can spend your entire time in insert mode, and then use <CTRL>-O to run an individual command.

Well of course you're getting a speed difference, look at how much extra work you're doing in the std::string code! The char[64]s are allocated once but you reallocate the std::strings every time. By pulling the declaration of s1, s2, and s3 to the top, I'm getting equivalent speed (g++ 4.4.7 with -g, 0.02s each time, clock() isn't any more accurate). And for essentially no runtime cost, you're getting memory safety and exception safety.

C++ is all about low-cost abstractions. Any speed difference between the C++ way and the C way should be very small, and the C++ way is safer. Use std::string (and std::vector and all the rest) unless you have a very good reason not too, and then you should probably just write your own custom implementation. Reverting to the C way is just asking for issues.

Carrier attack groups have a refueling ship along with all the cruisers/attack ships. It probably makes sense, just going by the size differences the carrier would use more conventional fuel than all of its escorts combined, so having the carrier be nuclear powered doubles your range.

Is this comment real? You made this comment on a site that most people use to waste time, and where one of the top posts is an Assembly implementation of Flappy Bird.

Fun fact: HFT has an annual revenue ~1/50th[1][2] of Google's. What's worse: a few hundred people wasting their time moving prices of select stocks a few pennies, or several thousand wasting their time collecting scary amounts of data about you to try and get you to click an ad?

[1]http://en.wikipedia.org/wiki/High-frequency_trading#Market_s...

[2]http://en.wikipedia.org/wiki/Google

They are teams competing for trophies, though; the trophy is your money/market share.

But beyond that, artificial competition could be a good thing. The large companies have a lot of advantages over the smaller companies, like economies of scale and name recognition, but they also have an incentive to stifle innovation (either directly or indirectly through the Innovator's Dilemma) and erect barriers to entry. Allowing smaller companies to "steal" CEOs helps offset some of those advantages. Even if they aren't well suited to that role, the name recognition alone can be an advantage (just look at SolarCity).

But I keep going back and forth on this. Set the salary cap too high, and the small companies can't steal the CEO away. Too low and it doesn't properly reward them for the difficulties of managing 200k+ person companies. A proper middle ground, if it exists, would be hard to find and need constant adjustments.

That's not entirely true. The salary cap is because if teams paid the fair market value, the teams with a larger budget would be able to run away with it like the Yankees did in baseball (with over twice as many World Series titles as the next best). It keeps the league artificially competitive.

Keeping the business world artificially competitive is an interesting idea, and not as bad as I initially thought.

If that's what made him your favorite, you really need to read his earlier post that really blew up in popularity. It's a great read. http://stilldrinking.org/programming-sucks

No, there is no downvote for posts. Flagging is supposed to take the place of that, but only for posts that violate the rules. From the FAQ

  There are no down arrows on submissions. They only appear
  on comments after users reach a certain karma threshold.

Photons have no rest mass, but one of the key points in GR is that mass and energy are interchangeable by E=mc^2. Mass-energy equivalence is how Fission bombs work.

You're right, the period was "hand picked", but that's because I was looking at a 5 year graph with the high and low marked, and just used those numbers. The movement before/after 2008 wasn't the 40 percentage points that would be needed for the hedge funds to do as poorly as the market, so I didn't bother.

But I just looked the exact numbers up. The S&P 500 opened January 2nd at 1467.97 and closed December 31st at 903.25. A 38.5% loss instead of the 60% I said, but that's still almost twice the loss of the hedge funds.

The second point is actually a point for hedge funds. The S&P 500 went from a high of 1576 near the end of 2007, to a low of 666 in the beginning of 2009 (October 07 to March 2009, specifically). Commodities had similar losses. If hedge funds only lost 20% when the general market lost almost 60%, they are a pretty good hedge against risk.

While the other answers about Sabre are probably right, I've heard that banks intentionally have stupid password policies to prevent password reuse. If one bank says "no special characters but most contain a number", another says "must contain a special character, but no numbers", and a 3rd says "must contain a number and special character", they can guarantee that if one of the 3 is hacked into it doesn't compromise people with accounts at all 3 (of course ignoring people using "password" with a 1 or ! on the end).

When this originally came up people were saying that, they use it as a reminder to keep using the site. But you can get the same benefit using a login link or something, no need for all the security issues.

A kill switch wouldn't have saved them. What killed Knight wasn't the $400 million loss, it was the lack of confidence all other firms had in them afterwards. Brokers can't just shut down in the middle of the trading day.

They managed to raise the money to cover the loss, but afterwards they were getting round 10% of their normal order volume [1].

Somewhat ironically, the closest thing they had to a kill switch, backing out the code, actually made the situation worse as it made all 8 servers misbehave instead of just the first one[2].

The full SEC report in [2] is an interesting read, just skip the parts about "regulation 5c-15...".

[1] http://www.businessinsider.com/look-how-knight-capitals-trad...

[2] http://www.sec.gov/litigation/admin/2013/34-70694.pdf

Related, Google built their own water treatment plant at one of their data centers.

http://googleblog.blogspot.com/2012/03/helping-hooch-with-wa...

They should do it only in situations where it doesn't change the program behavior. I use memset frequently in C just to be safe, but if it's written to later on before it's ever read from, the compiler can optimize that away. I'm guessing their recommendation here is if you did something like

    char* plain_text = malloc(size);
    ///do stuff with plain_text
    memset(plain_text, 0, size);
    free(plain_text);

For most programs that last memset is unnecessary (and may even be unnecessary according to the standard, but it's probably implementation defined, not undefined behavior) and it makes sense for the compiler to optimize it away. But for crypto purposes you have to be afraid of someone being able to read plain_text later, so the memset is important

The NYC equivalent is losing money because everyone got a annual pass and not many tourists are using it. The tourists are the real money makers, as only 10 daily passes or 4 weekly passes will be the same cost as an annual pass[1].

If I was the program director though, I wouldn't be worried yet. We just got out of the coldest winter in recent years, and in a few months we can tell if no one is riding the bikes because the novelty wore off or because it was cold.

http://www.citibikenyc.com/pricing

You completely missed his point about the difference between non-public information and new analysis on public information. Anyone can go and count the number of cars in a WalMart parking lot. This is new analysis on public information, not non-public information.

Except you completely missed the point where Ackman isn't making any money off this.

> Mr. Ackman has said he will donate any profits he personally earns to charity, calling it “blood money.”

And that's ignoring the fact that we live in a capitalist society. You need money to get things done. If no one stood to make a profit from this the effort wouldn't be nearly as well run. This is the market working at its best (at least in principle), rewarding people who put in lots of effort to reveal information that benefits the public.

Quite honestly, I'm surprised it's that low. 37% of households in Manhattan make over 100k/year[1]. Take into account that taxis are mainly concentrated in the high income areas (read: not Harlem) and the "nearly half" works out to basically the demographic split of the area, not the result of trying to keep poor people out of cabs.

Also, before anyone points out that the limited supply is keeping taxis out of the poorer areas, there recently introduced boro cabs[2] are meant to solve this specifically, with limited areas where they can pick up passengers and a much cheaper medallion ($500/year instead of ~$200k/year).

[1] http://factfinder2.census.gov/faces/tableservices/jsf/pages/...

[2] http://en.wikipedia.org/wiki/Boro_taxi

Going along with what someone said earlier, your last question can be "Were you born after someone who answered the previous 32 questions the same as you", which works to identify twins as well as people in general. Although I don't know how this would work for triplets (or any larger number of "twins" than 2); you'd have to make the previous 32 questions split them into groups of at most 2.

You misunderstand the point of the FSF. It's free as in freedom, not free as in no money. The whole thing started because rms wanted to modify a printer driver to give functionality their last printer had. He wasn't being stingy, he just wanted his workflow back. The FSF has no problems with charging for software, they have no objection to Red Hat, for instance, charging for the GPL Linux kernel (although they have other problems with Red Hat). The FSF is concerned with users having access to the source, not with everyone being users or non-users having access to the source.

If I remember correctly, the most efficient algorithms have a ridiculously large constant factor, to the point where you don't have enough RAM to even store the matrix, let alone do anything with it.

I hope everyone learned their lesson after all the panic over Italy/Greece/whoever defaulting and when senior MBS bonds took losses way back in 2009 and the code can handle defaults. I think the bigger risk would be from the portfolio rebalancing that would need to be done as what was assumed to be a 0 risk T-note is no longer 0 risk. That's of course ignoring the sudden "oh shit" heard all the way in southern Jersey when the notes don't actually pay out.

There's also what's called prepayment risk (or in this scenario I guess late-payment risk, but they're 2 sides of the same coin). For prepayment risk, essentially an investor thinks "OK, I put a lot of effort into this investment, but I don't have to worry about it for another x years". But the next month the investment returns at say a 15% yield, which would normally be great, but now you suddenly have to figure out what to do with that money and there may not be a similar quality investment around, at least one that's easy to find.

In this case, the bonds are such short term that the banks are probably using them basically as cash on hand to pay bills that are due at the end of the month or something while getting some return along the way. If the payment is delayed (or god forbid defaulted on entirely) suddenly they can't pay their bills. Then they have to either pull out of their other investments early (which will drop the prices of those investments), or turn to their own bond holders/power companies and say "it's not our fault we can't pay, it's the governments" which leads to a not-so-nice cascading effect. That's why Wall Street is so unsure what will happen, they aren't sure what they can do in the situation and how far their actions will cascade out.

The kicker is located in the middle,

> The median 401(k) balance for households headed by people aged 55 to 64 who had retirement accounts at work was $120,000 in 2011

The 77 year old highlighted is just an easy way to personalize the larger statistics.

Ratings are done at a bond (tranche) level, not a collateral level. Rating them at the collateral level would be incredibly stupid as some bonds are specifically designed to take loses in order to bolster the ratings of the senior bonds.

Also, the entire point in creating these structures is to introduce the multiple and very different risks. You start with collateral that is exposed to a bunch of different risks, and you end up with bonds that have only 1 specific and unique risk (in theory). Then whoever buys the bond only has to worry about hedging that one specific risk (or using it as a hedge for that specific risk) instead of trying to balance 5 or more different hedges.

If you want to be understood, you have to make sure your point is clear. Throwing in an unnecessary controversial point, especially about someone as divisive as Jobs, just muddles pg's main point.

Lowering the interval makes the effect less pronounced, but it's still there. When you have fixed intervals the order book will keep increasing in size until the trades execute on the 1 second interval or whatever it is, and the book will be larger than for our current instantaneous ticks. Larger book means wider spread, as basic game theory says when you have more participants you need a stronger hand to have the same odds, so if you want that trade to execute you put it way outside the last price. HFT firms narrow the spread and take the difference as profit, as they don't really care if 1 particular order executes so they play closer to the last price.

Randomizing the execution order makes the spread even wider, because now you need to beat everyone instead of just tying if you want to guarantee execution. And again, the HFT firms don't care if any particular order executes. Although randomizing the order would probably reduce the incentive to co-locate, but I'm guessing the larger firms would still want quicker access to the last price, just in case.

Also, in all of this I'm assuming no one outside of the exchange can view the actual book, just the last price. If you let people see the full book, as they can now, this is all a wash anyway as they'll just "trade" by placing and cancelling orders right up until the next tick.