lliiffee | 9 years ago | on: Planet Money: Self Checkout [audio]
lliiffee's comments
lliiffee | 9 years ago | on: “The Depressed Person” by David Foster Wallace (1998) [pdf]
It's a massive book, but it really is very entertaining as well. Give the first chapter a go, and if you're totally sucked in and laughing, you might be just glad that the book is as big as it is. If you aren't enjoying it on a page-by-page basis, it's probably almost impossible to power through. It's one of my favorite books, but it doesn't contain the meaning of life, or anything.
lliiffee | 9 years ago | on: FBI director: Cover up your webcam
Would you mind sharing any more details about the attempted blackmail?
lliiffee | 9 years ago | on: How Google obliterated my 4 year old Chrome extension featuring 24k+ users
That's a good point, but it also seems strongly correlated with those that run ad/privacy blockers. (Even with such a blocker, perhaps the data collected is still valuable, though?) My instinct is that by selling an ad and tracking-free site, they would be indicating that the ads and tracking are a bad thing, as opposed to the party line that it's all "to deliver better services to you".
lliiffee | 9 years ago | on: Itsy Bitsy Data Structures – Simplified examples of many common data structures
I definitely see your point! I guess there is a place for algorithms at any point on the easy/good trade-off.
lliiffee | 9 years ago | on: Itsy Bitsy Data Structures – Simplified examples of many common data structures
You could periodically delete the wasted space. I think that if you, say, delete the wasted space when it is equal to the used space, you still still have O(1) amortized time.
lliiffee | 9 years ago | on: Uber Loses at Least $1.2B in First Half of 2016
Taxis are craaaazily expensive in Japan. (The quality of service is high though, which perhaps you were referring to.)
lliiffee | 9 years ago | on: It Depends What You Study, Not Where
It seems unlikely-- in order to be true, computer science majors would need to actually have higher income with degrees from less competitive schools.
lliiffee | 10 years ago | on: Airbus proposes new drop-in airplane “cabin modules” to speed up boarding
I think brk was just saying that everyone in priority will have room for their bags. Without priority boarding, they would have to fight with everyone else.
lliiffee | 11 years ago | on: Numerical Optimization: Understanding L-BFGS
What I mean is that, if just doing regular Newton, I'm not sure I've ever seen an example using the interface you show. I think that the vast majority of Newton's method implementations pass H rather than H^-1, and get the search direction via "solve_H_g(H,g)" rather than "solve_iH_g(iH,g)". It takes cubic time to compute H^-1 from H (after which you can compute (H^-1)g) and it takes cubic time to solve for x such that H*x=g, but the rather is said to be more stable, and so preferred.
I know this is irrelevant to the main part of the post, which is to explain LBFGS, I'm just genuinely interested if there are applications where its better to pass the inverse of H rather than H itself for some reason.
lliiffee | 11 years ago | on: Numerical Optimization: Understanding L-BFGS
Is it typical to interface to Newton's method via a function that computes the inverse Hessian? I've never seen that. Typically, people claim it is numerically unstable to explicitly invert the Hessian, and that it would be better for the interface to take the Hessian itself, and then call a subroutine to do a linear solve.
lliiffee | 12 years ago | on: Flappy Bird Typing Tutor
Doesn't seem to work in firefox? (The search bar keeps getting activated.) I think I have the "automatically search on typing" option selected though.
lliiffee | 12 years ago | on: Machine learning is easier than it looks
Great questions! I can answer a few of them.
- Yes, you can get stick in a local maximum. However, see the k-means++ algorithm for a clever initialization scheme that gets you within a good constant factor of the global maximum.
- The best way to pick K is to fit the algorithm with a range of K and see which K seems to give the best application performance.
- It is "your job" in creating the feature space to ensure that feature-space nearness corresponds to application-space nearness. This is not easy at all, and essentially the only reliable test if you've done a good job is if the final algorithm performs as you'd like it to.
I think that the post is really observing that, once you understand it, ML algorithms aren't really that complex. However, once you understand it, most things aren't that complex, and that doesn't make fully understanding them easy in the first place.
lliiffee | 12 years ago | on: New US $100 bill to debut Tuesday
I have to disagree. The potential downside for a flaw in the new bill could be rather catastrophic damage to the economy. The downside of a failure with the Mars rover is that the rover just doesn't work. Thus, it makes sense to be dramatically more conservative in designing a new currency.
lliiffee | 12 years ago | on: The fate of published peer-reviewed articles, submitted again (1982)
I totally agree-- the problem with reviews isn't technological. Reviewers fundamentally need better incentives to do a good job, which I'm not sure how to do.
lliiffee | 12 years ago | on: The fate of published peer-reviewed articles, submitted again (1982)
There are lots of things you might consider, that would be impossible with snail mail. For example, the reviewers might be able to send regular emails with questions to the authors, or the authors might be able to constantly update the paper in response to initial reviewer comments, there could be an anonymous "chat room" of some kind, etc. Not sure if any of these are good ideas, but I think it is a fair point that most journals simply use the internet as a "faster snail mail".
That said, I review for conferences that are taking advantage of the internet, with author response to reviewer comments, discussions among the reviewers, etc.
lliiffee | 13 years ago | on: Julia, I love you (2012)
Actually, it takes real effort to make GCC not completely optimize-away this kind of stuff for C:
lliiffee | 13 years ago | on: A year without caffeine (part 2)
There is evidence of a bunch of mild benefits (and also mild risks). I'd currently say it looks like a small net benefit, but with a confidence interval that would include negative territory. In general, it seems reasonable to drink coffee if you like it. It certainly is an addictive drug, though.
lliiffee | 13 years ago | on: Marijuana Majority Website Highlights Celebs And Tech Leaders Who Support Pot
If the current penalties remained in place for smoke-driving there would be no increased incentive to drive while stoned. In general, I think the problems you bring up are perfectly valid, but I see no fundamental reason society should deal with them differently than with alcohol.
lliiffee | 13 years ago | on: 42% of US Internet Users Have a Facebook Account. For Twitter, It’s 16%
Well, the confidence intervals are right there on the charts, and look pretty damn significant to me...
I also generally found them to work better in Australia than in the US, though the technology seems to be the same. I guess it's because of these tolerances being set differently, but that's just speculation.