B-Trees actually have superior cache performance compared to other types of trees (such as T-Trees or BST Trees). In part, this is because B-Trees have a higher density of actual data to pointers.
There is a tradeoff of computation (doing binary search inside the node) and amount of storage (keeping less pointers). In environments where memory access is much more expensive than a CPU instruction, it is preferable to perform these computations than to have to read all the extra pointer data to jump to the right places.
In fact, a breed of cache-friendly data structures are precisely based on the B+Trees but with even less pointers, having the algorithm compute these pointers instead (CSS-, CSB-Trees)
It is clear to everybody that iMessage is not a platform-independent to send messages today. Thus, there is still a need for BBM, SMS, and all.
However, the distribution of people who own iPhones is not as uniform as the author seems to imply. Sure, maybe there are only 5 iPhones for every 95 other phones; however, I know my girlfriend, parents, and close friends all own at least one iOS device. The service will remove the need for SMS for those who are in the same situation, and the extent to which this happens is not addressed here in any valuable form.
It is also true that GTalk may have a higher usage, and I'd be thrilled if iMessage worked with GTalk (I think). However, iMessage will be tightly integrated into the Phone application, which makes it much more convenient to use than any other IM service on the iPhone. Maybe iMessage/GTalk interoperability would make iMessage more effective; this doesn't mean as it stands iMessage will be ineffective.
You've probably seen this already, but have you considered the Harvard Extension School? I don't know the details, but I do know the extension school offers some classes taught by the same professors that teach regular Harvard classes.
An example of these classes is Prof. Michael Mitzenmacher's algorithm's class, which is both challenging and fun. I think the class is offered online and maybe in person during the summer.
(http://www.extension.harvard.edu/2010-11/courses/21462.jsp?c... )
Yeah I am aware of the Harvard Extension school. They require an on-campus course up front but it would be a big pain for me to go to Cambridge for that. Not to mention it is a writing course which is something I have already done elsewhere.
The difference, of course, is that people these days are quick to say how much they use Facebook or OKCupid, but very few people are willing to talk with their friends about their extramarital affairs.
It is sad to see some areas where people on average are doing significantly worse than the richest parts of the United States.
However, I find the choice of the term 'Third World America' to be particularly deceiving. Let's take Louisiana, for example, marked as amongst the worst regions according to the infographic. Median earnings are 28,000 and about 75% with at least high school education.
Now let's compare against Mexico's average. Mexico is not nearly as bad as other third world countries. Average earnings are about 7,000 USD/year [1] (and median earning is probably worse). Roughly have of Mexicans haven't completed their junior high school education (6th to 9th). These are national averages, though, which --unlike the infographic -- do not focus only on the poorest areas. The poorest areas are, of course, much worse.
I'm not trying to say with this that you shouldn't complain if others have it worse. I am just saying that this particular choice of wording is not realistic and, in my mind, took away from the credibility of the rest of the site .
I don't get it either. Why the ongoing comparisons with countries that are even worse off? Wouldn't it be better to look at countries in which there is less poverty, and see what they do better?
(For example: many North European countries hardly have poverty as in "can't pay for food/housing" at all)
Because that angle has been tried repeatedly and is usually shrugged off by conservatives as 'too European, too socialist'. So, this is an attempt to point out that we're not in great shape and shame politicians into doing better for the people.
Conservatives will find it even easier to shrug off comparisons between the indebted, undereducated and underemployed in the US and the extreme poverty of the "Third World".
Whilst there is a significant amount of evidence to suggest that relative poverty is actually more detrimental to people's happiness than absolute poverty, comparisons like this which conflate the issues and don't provide any stats to back their claims up are counterproductive.
I'm not saying extreme rhetoric doesn't work (see for instance effective campaigns which characterise a lifestyle more than half the world would consider well-off as a "living wage"), but I don't think it helps in this instance.
I think this angle doesn't work either. At least, on a personal level it wouldn't work: You can't shame someone who's not doing so well into performing better, by pointing at people that perform even worse. They would reply with "Right, so I'm doing comparatively well?".
BTW: I find it very typical that our posts get modded down.
I wouldn't call it to 'tweak' the data collection. He is simply normalizing the results to ignore the differences in language distribution.
This is normal and has nothing to do with how you choose to represent it.
It would have been meaningless to show any graph or table saying 'Python has the most messages with profanity" if the amount of Python projects is 80% of all the projects out there.
He is right to normalize the results, but parent's point is that he is wrong to do that by modifying his data collection.
He should just collect as many commit messages as possible, then divide the profanity count for each language by the commit message count. Because that has lower standard error [and no more bias] than what he did.
The link is not working for me; going to http://twitter.com/NokiaPlanB/ only shows the following quote: "there are no 'nine young investors', just one very bored engineer who really likes his iPhone"
If this is the case, then I guess that explains the anonimity.
They have fixed costs (independent from the number of tickets bought) in the form of payments for search results to ITA plus whatever company overhead (maintenance, salaries, etc).
Whether Hipmunk can afford improvements in user experience while earning thinner margins than the competition is not entirely obvious to me.
Hipmunk will grow up living on whatever profit margins they end up being able to generate. Kayak at this point could not learn to live on significantly less.
