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textminer

354 karma · joined July 17, 2012

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textminer··on I Wasn’t Prepared to Work
About to start a daily commute from Berkeley to Menlo Park. Am optimistic about 880-South in the morning, and driving seems far faster and more peaceful than the BART -> Shuttle method. But I do mourn the loss of productive time on a daily basis, but can't imagine a better place to live. Even on a wonderful developer salary, I cannot possibly afford a nice apartment for me and my partner in San Francisco or on the peninsula. Especially compared to East Bay's prices...
textminer··on Poll: Full-time software engineers in the Bay Area, what's your annual salary?
My suggestion is to avoid telling a potential new employer what you make now. They'd then work hard to cap you at current + 30% instead of what a comparably-skilled peer might make.
textminer··on Machine Learning as a Service
Random Forests are nice in having few parameters-- number of trees, number of restricted features to sample on at each decision node.

It's the variations on the standard RF that have interested me. Rotation Forests, where features are partitioned randomly and rotated (by PCA or random projection) before decision boundaries are drawn. Extremely Randomized Forests, where the node splits are completely random and not based on best possible Gini/Entropy gain along some feature. There's even an interesting use of deterministic annealing out there for incorporating unlabeled data points in an attempt at semisupervised learning.

These each have their own parameters to tune, but have had slightly different performance on different problem domains. Even models require different data-- most decision trees have a quite natural way of imputing missing values, but something like a Rotation Forest can handle neither missing values nor categorical data (unless you map it to m binary features). And that complexity spooks me away from Machine Learning as a Service, where one could start failing to understand his or her models. (Plus then I'd probably be out of a job.)

textminer··on What does O(log n) mean, exactly?
I work in machine learning. I regularly get jazzed when I figured out a linear solution to a problem (e.g., using a min heap to grab top k elements from a similarity computation in a recommendation system instead of first sorting), and will remark on such to anyone I'm working with. In more mundane settings, I'll also regularly use, say, hash tables to store data for convenient constant time lookup instead of naively scanning through a list each time I need to find an index.

I think I can safely say that asymptotic time and space concerns of a problem firmly guide much of my choices in data structure and algorithm use. Though this is maybe followed closely by aesthetic pleasure, novelty of trying something new and neat, or clarity in the functional organization/readability/maintainability of the code.

textminer··on Unsupervised Feature Learning and Deep Learning Tutorial
Learn and be well: http://www.iro.umontreal.ca/~bengioy/papers/ftml_book.pdf

Explains and motivates the use of autoencoders (and sparsity constraints) and restricted Boltzmann machines, too.

textminer··on Unsupervised Feature Learning and Deep Learning Tutorial
Am I crazy, or is the short-run benefit more for unsupervised feature learning more than classification accuracy? If I recall from my brief reading on the subject, kernel-aided SVMs and Random Forests are basically equivalent to a three-layer deep graphical net, but on painfully feature-engineered inputs. I'd wager learning features is more useful now than any benefit of a super-deep architecture.

(I would love for a practitioner to shoot this down or corroborate my hunch-- awfully new to neural nets, having basically read a monograph, played with Theano, and watched some Hinton lectures.)

textminer··on Getting a job in San Francisco
For the long-term career-conscious and money-hungry, it almost makes you want to plan a trajectory that doesn't plateau at "senior engineer". That seems like a shame/misuse of resources, doesn't it?
textminer··on Getting a job in San Francisco
In this vein, it's been hard to fully appreciate San Francisco. I can "see" the lovely homes in Duboce Triangle and the Castro and in Hayes Valley, and I can "enjoy" the way the earth bends around you on a North Beach rooftop. But being in San Francisco has, for me, had stronger class-resentment associations that stem probably from having commuted there from East Bay and being in a constant "work work work" mode for young entrepreneurs whose flaws have been hard to overlook.

There's probably a fair degree of resentment at being unable to afford a decent apartment in the city. I imagine my tune'd be different had I lucked into something livable in a cool neighborhood, rather than living in an assortment of East Bay towns and commuting by BART.

I'll be working in the peninsula soon, at one of the giants, and that will have its own joys and issues. But I'm looking forward to seeing how my view of SF evolves, as it'll soon merely be that city across the bay I visit for dinners, shows and drinks.

textminer··on How I Turned Down $300,000 from Microsoft to go Full-Time on GitHub (2008)
This was inspiring in a way many "how I started a company" posts aren't.

I also appreciated the transparency re: the retention package offered to him in the Powerset acquisition. As a younger engineer, I've spent a lot of time focusing on salary numbers (going from $70k to $90k to $100k to $122k in a few years, and across a few companies), but I'm starting to see how that's less informative than bonuses/stock grants, where the real long-term incentives and house-buying/lifestyle-company-starting capital comes from.

Are there forums where folks openly discuss numbers like these? Glassdoor can be confusing sometimes, where it's unclear if folks are putting down their pre-tax salary number or their [salary + sign-on + annual bonus + RSU] number.

textminer··on Greek Yogurt’s Dark Side
Why is so much of it non-fat?! The 2% milk fat Greek yogurt is so much richer, adds a trivial number of calories, and requires almost no sugar to taste "good".
textminer··on NY official: Airbnb stay illegal; host fined $2,400
Isn't that less the externalities than the pool of folks using the existing hotel infrastructure (bending supply/demand) rather than exploring AirBnb/couch surfing/etc. I imagine if business travelers and tourists used AirBnB en masse, the prices would more closely approach that of traditional hotels... But with hosts that're less dependable.
textminer··on U.S. Software developer wages fall 2% as workforce expands
Am I the only one driven crazy by reporting that states an ambiguous "average" for something asymmetric like salary, when the choice between median and mean as a measure of centrality makes all the difference in the world?
textminer··on Source code example of the Shazam algorithm
Over a Fast Fourier Transform?! That's like saying an SVD or a decision tree constitutes a trade secret.
textminer··on When you shouldn't bother unit testing
The argument against testing seems to be "the Spike", when you're learning a language/concept/framework or are testing out ideas. But startups (at least the two I've worked for the last two years) seem way more heavily invested in the spike than in the carefully-tested production environment. Personally speaking, it's even more exciting to work on.

It took me a good year and half to properly appreciate well-optimized, well-tested code in production, and enjoy the challenges associated there (which aren't trivial-- the neatest, ugliest NumPy script can be entirely useless at scale, or in a timeframe useful to users).

But I still personally feel flat when the knowledge gains associated with a Spike aren't as frequent. How have other developers and math-types dealt with that disappointing feeling of a plateau? Besides just changing jobs entirely, I mean.

textminer··on Buzz Aldrin: Get to Mars within 20 years
Only because it'd spectacularly fail.
textminer··on Buzz Aldrin: Get to Mars within 20 years
I don't think it'd be the folks living in a paradise. It'd be the folks fleeing persecution or economic horror. Why'd folks leave Europe for the New World, or any other migration? (And I mean the early ones-- not the gold rush-thinkin' ones.)
textminer··on Buzz Aldrin: Get to Mars within 20 years
Are you sure on the first part? My read of the historical narrative is that folks attribute the success of Apollo to JFK, not Nixon, and not Johnson. However wrong or right.

(It should be pointed out that I was born in the mid-80s, and am frequently distracted by cat memes. But I have briefly worked for NASA.)

textminer··on Buzz Aldrin: Get to Mars within 20 years
I fully agree. But only because an American colony on Mars would be aesthetically preferable to a SpaceX corporate colony on Mars, where colonists'd predictably work fifteen year sentences as indentured servant miners to pay off their voyage.

Also, an extension of our country on another planet would probably be the first move toward humans getting past statism entirely. But that's just a guess/hope.

textminer··on Richer countries are happier than poorer ones. Richer families are happier too
And even if you only see a few people richer than you, in a place with a high Gini coefficient, they're probably much richer than you. Human brains like to linearly extrapolate, so you probably assume that that non-linear explosion in growth doesn't mean you're 98 to their 99, but that you must be 80 or so.
textminer··on Managers to Millennials: Job Interview No Time to Text
Where's the FUD about recent college grads in the 1960's interviewing for jobs with full, unkempt beards, and making allusions to radical politics?
textminer··on Founders: Don't Forget to Sell The Dream
(Just in case my comment sounded parodic because of my self-description, or contrarian because of your call for public bravery, it wasn't meant to be either.)
textminer··on Founders: Don't Forget to Sell The Dream
I find your comments to be spectacularly useful. I'm a twenty something machine learning developer with a functional bent and high expectations for rewarding stimulation in VC-land, and you've recapitulated many of my own thoughts and conclusions spectacularly well. Would you mind if I bent your ear about a dilemma over private channels?
textminer··on Machine Learning and Link Spam: My Brush With Insanity
If using raw bag of words or n-grams, why not hash the strings to maybe 2^13-1 slots, with something like MurmurHash3 or with multiple hashes to prevent collisions, then use that sparse vector as input to a deep learning model?
textminer··on Facebook Home ads show Facebook at its worst
I don't know. Beach pictures, drag queens (Shangela jumps out of a box!), cute kids, kitty cats, and club photos basically describes what I see the service as being used for by my chums. Not a bad diversion for keeping up with far-flung friends, in my honest opinion.
textminer··on How Kaggle Is Changing How We Work
Don't mean to poo-poo. I love scrambling for models and methods. In the latest problem I worked on, I did the same thing. Implementing papers, trying to avail myself of semi-supervised or reduced-dimension representations, tweaking models and features every which way... it's illuminating work, and good things come out of it.

But, in the end, companies like Netflix or where I work are immediately looking for cheap ways to make X happen easier, better, and cheaper. But then hopefully the smart papers go on a shelf or are easily Googleable, and the rest of us get to learn from their efforts.

I can fit long-term and short-term goals in my brain, too, mister.

textminer··on How Kaggle Is Changing How We Work
If I recall, BellKor made many, many models based on Gradient Boosted Decision Trees, Restricted Boltzmann Machines, and kNN. They tried many different feature subsets, added temporal weighting, and tried many reduced-dimensionality representations (SVD, NMF). They then stacked them all together into one final ensemble whose RSME beat everyone else's on a hidden validation set.

In a production environment, this is probably an insane amount of transformation, feature extraction, and classification for marginally little gains in precision (as defined here). But I'm only a year or two in to building production-environment classifiers, and nothing at Netflix's scale (though not tiny either-- it is a problem if I can't do feature extraction and high-precision/-recall* classification within a few milliseconds).

* - mid 90s, for a hard NLP/social graph problem.

textminer··on "Put down the crack pipes" doesn't go so well
"Did you fall off a space elevator or something?!"

Only because it might compel some contrarian to build a space elevator. And I really want a space elevator.

textminer··on Which programming languages should I learn: Beginners Edition
Can't stress the importance of a REPL enough. The hands-on interactivity, call and response, and introspection pushes your understanding of the language (and ability to build out astounding new ideas) so much more quickly. Also love that he highlighted Logo and Basic, which is exactly how I learned programming. The former in elementary school computer labs, the latter as a young kid on the family's 386, eager to make my own version of Nibbles.
textminer··on Abusing hash kernels for wildly unprincipled machine learning
I love this entry. Two months ago, I wrote a perhaps more-pedantically-technical entry about the hash trick and its use in building a simple classifier, even making it play nice with Scipy's sparse linear algebra (eventually writing my own CSR times CSC multiplication method in Cython): http://blog.newsle.com/2013/02/01/text-classification-and-fe...
textminer··on Imperative vs. Declarative
Oh, now I have to yell at myself. No doubt Python's sorted is some n*logn quicksort, and not actually in quadratic time. Crow for all!
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