jwmerrill

29 ms·

241.
by jwmerrill 13y ago
I would not recommend that circular buffer idea for quantitative calculations. Consider averaging n numbers from a buffer that you've filled with m random variates with m < n: the standard deviation of your average will decrease lik
242.
by jwmerrill 13y ago
Nice! In case it isn't obvious, randn! takes an existing vector and fills it up with new random normal variates. This allows computing a bunch of random variates at once, which is a little more efficient, without having to allocate a n
243.
by jwmerrill 13y ago
Monte Carlo simulation in general is definitely performance sensitive. If you're averaging over realizations of a process, the accuracy of your estimate typically depends on the square root of the number samples you take. For a given t
244.
by jwmerrill 13y ago
Here's a gist that optimizes the author's Julia code to give a 4x speedup over the unvectorized code, and handily beat the vectorized codes too: https://gist.github.com/jwmerrill/9715447 In general, carefully
245.
by jwmerrill 13y ago
You might also enjoy https://www.desmos.com
246.
by jwmerrill 13y ago
PJs https://github.com/jayferd/pjs is the sanest js classical inheritance library I've seen. It's very lightweight, doesn't mess with Object.prototype, and interoperates seamlessly with coffeescript clas
247.
by jwmerrill 13y ago
Clearly, you aren't familiar with Zed's oevré.
248.
by jwmerrill 13y ago
Sorry for making you feel sad. Good points all around, here, and in the other comments about GPUs. Regarding CPU, though, my understanding is that on a 64 bit machine, 32 bit arithmetic is no faster than 64 bit arithmetic. Is that incorrect
249.
by jwmerrill 13y ago
Who's using single precision floats these days?
250.
by jwmerrill 13y ago
The call to Stripe.charge.create is blocking, in the sense that the server can't start processing a new request while it's busy waiting for a response from stripe in an existing request, right? I think this kind of use case is exa
251.
by jwmerrill 13y ago
Quick reimplementation in the desmos graphing calculator: https://www.desmos.com/calculator/brjshfkaof Press play next to t_0 to animate.
252.
by jwmerrill 13y ago
Brightness decays exponentially for light traveling through smoke: https://en.wikipedia.org/wiki/Beer–Lambert_law . But I think the article author probably just messed up.
253.
by jwmerrill 13y ago
It looks like Factor passes all of these tests. Hat tip to Daniel Ehrenberg.
254.
Arb: a C library for arbitrary-precision floating-point ball arithmetic(fredrikj.net)
2 points by jwmerrill 13y ago|0 comments
255.
by jwmerrill 13y ago
This rebuttal doesn't seem to say that much about Lustig's central claim: that fructose is metabolized in a very different way from glucose, that large amounts of fructose metabolism harms the liver, and that this harm may be asso
256.
by jwmerrill 13y ago
Here's a gist showing the basic steps, using the unix utilities host and netcat: https://gist.github.com/jwmerrill/6502014
257.
Chebfun: Numerical Computing with Functions(www2.maths.ox.ac.uk)
2 points by jwmerrill 13y ago|0 comments
258.
by jwmerrill 13y ago
Would you mind expanding on how to implement these steps, or do you know a good reference?
259.
The Lords of Vendorbation(zeldman.com)
2 points by jwmerrill 13y ago|0 comments
260.
by jwmerrill 13y ago
Array.map/filter/forEach aren't just slow because of function call overhead. They have different semantics than the for loop that you'd typically write (and that Coffeescript generates), because they support things like
261.
by jwmerrill 13y ago
Can you expand on the one pass algorithm, or provide a link? There was a two pass variant at the end of the paper, but I didn't see any explicit one pass variant.
262.
by jwmerrill 13y ago
The short study and the long study apparently disagree about whether 12hr or 24hr access to HFCS results in more weight gain. The 8 wk study shows 12hr HFCS leading to much larger weight gain than any of the other groups, and 24hr access no
263.
by jwmerrill 14y ago
Incrementing undefined gives NaN. You're going to want to initialize that i to 0.
264.
Efficient Aggregates in Julia(julialang.org)
4 points by jwmerrill 14y ago|0 comments
265.
by jwmerrill 14y ago
The concept you're looking for is "independence" http://en.wikipedia.org/wiki/Independence_(probability_theor... The glow worms are still distributed randomly in the mathematical sense, but knowing the position of one tells you something
266.
by jwmerrill 14y ago
Common parlance "random" seems to mean something more like "uniformly distributed and independent."
267.
by jwmerrill 14y ago
I think what iOS brings to the table here is Newsstand and its subscription model. This is probably more important than any technical layout advantages. The open web is great, but I think its also valuable to experiment with a platform wher
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by jwmerrill 15y ago
You actually can get access to these apps in other browsers through the Chrome Web Store. Try adding any of the Drive enabled apps. The experience is a little odd right now, but it works.