adolgert

8 ms·

31.
by adolgert 12y ago
If you search for "fibonacci grid sphere," you'll find the grid used for research. It's less regular and a lot more work, with a few regions of five or seven sides, but it might look more natural, and it's used beca
32.
by adolgert 12y ago
I like that paper. Thank you. It has references which criticize the skipahead technique. I need to look into whether I believe that paper, though. There are lots of ideas about how to do this, and subtle flaws abound. While many generators
33.
by adolgert 12y ago
Do the Monte Carlo people all know about Barash and Shchur's work? They made an RNGSSELIB and PRAND (using NVIDIA cards), but the main contribution is that they incorporated a new way to generate multiple streams not by re-seeding the
34.
by adolgert 12y ago
This is an interesting application, and dogged mathematical derivation, of survival analysis. We would do the same calculations today with standard Kaplan-Meier curves. Do you see the survival functions, S=1-F, in the first few pages? They
35.
by adolgert 12y ago
My recent favorite reminder of why I need others in order to program well is the list of things I am unqualified to say about my own work, including, but not limited to - Is the user interface intuitive? - Will this library be efficient for
36.
by adolgert 12y ago
Haven't read it unfortunately. The table of contents shows a much more rapid treatment. When working outside of a university course, examples can be very useful. Anyone else read Burke?
37.
by adolgert 12y ago
Enough of you care about this to vote it to the front page? Who are you people? In that case, I have two favorite books on this topic. Bamberg and Sternberg, A Course in Mathematics for Physics Students. It's a redo of calculus using d
38.
by adolgert 12y ago
It was a year after this paper that the Fenwick Tree came out. It compresses storage for the prefix sum into an N-length array instead of 2N-1. This is what's used in stochastic algorithms for chemical reactions.
39.
by adolgert 13y ago
There's an algorithm to deal with this kind of additive small error, the Kahan Summation algorithm. It keeps a second number to record the residual of an addition so that adding something small to something large doesn't go awry.
40.
by adolgert 13y ago
Her CSPAN video: http://www.c-span.org/video/?c4486712/sen-feinstein-accuses-...
41.
by adolgert 13y ago
It's not common metal. The design of the slug is much of the work in creating a railgun because the electromagnetic push comes from generating back-currents within the slug itself. It has to be good at being pushed, then good at flying
42.
by adolgert 13y ago
Maybe you looked at Schroeder and Gibson from Fast07, which looks at MTBF calculations. They have lots more data, but none released. Hard drive failures are an easy example of the use of the concept of hazard to examine probability distribu
43.
by adolgert 13y ago
The javascript shows they are thinking about this as particle traces of wind velocities. In visualization, the technique is called Line Integral Convolution (LIC). Each line follows the direction of the wind vector, and the overall brightne
44.
by adolgert 13y ago
It makes me so happy to see such a clear picture of how service logs relate to the input and output token streams of finite state machines. We usually think of finite state machines as these little objects with a few states, but the categor
45.
by adolgert 13y ago
Meyers' presentation slides, with notes, are available and excellent: http://www.artima.com/shop/overview_of_the_new_cpp . They include C++14. It isn't the deep dive, but it's a great overview.
46.
by adolgert 13y ago
Maybe more apt a comparison would be a choice between custom-built automobiles and those from factory lines. At the time, there was fear that working in factories was dehumanizing. The ethical question is resolved politically, by having lab
47.
by adolgert 13y ago
Is there a significant ethical difference between purchasing from a store or from a large online retailer? In one case, shipping to the store is bulk, and employees may make low wages, but they interact with other people. For a retailer Ama
48.
by adolgert 13y ago
It was relatively common in the CAVE to have someone see in stereo for the first time. The shutter glasses have LCDs that are synchronized to flip black and then clear, alternating eyes. The projectors are synchronized to this flip so they
49.
by adolgert 13y ago
That's an excellent question. Latitude and longitude are straight in the projection he is most likely using, but great circle arcs are what we consider straight on the globe. The kicker is that most political boundaries are neither. Th
50.
by adolgert 13y ago
Mosquitoes in the US used to be mostly Aedes, but now there are a lot of Culex, which fly twice as fast (120cm/s, or about 2.7 mph) and are better hunters. The Aedes come into a room, find a wall, and eventually eat, while Culex go str
51.
by adolgert 13y ago
For the coronovirus, people tend to check the type of infection only when the infection is bad. The people who have died all had comorbidities, meaning they were already sick with something else, so that 50% death rate is a result of a very
52.
by adolgert 13y ago
Ah, I missed their explanation. The 196% and 338% are still bizarrely high figures, given that the variance of a Poisson distribution equals the mean. 338% variance, and you don't ask what kind of distribution you're measuring?
53.
by adolgert 13y ago
Statistics would help us believe this article. Are they quoting 196% variance over the mean? What does it mean to be 4.5 times smaller? Even the basics are amiss here. There are a lot of conclusions from just two examples of highly complex
54.
by adolgert 14y ago
This multiplicative kind of model is happily amenable to time series analysis, so you can do stats to see what your numbers are and how well they fit. That's great. What's less great is the model quality, given that well-tested virality mod
55.
by adolgert 14y ago
The grammar of Vega is a description of visualizations, but it isn't a grammar for computation of visualizations. That's where these tools fall short for me, in the sense that they fall short of VTK, VisTrails, and even old OpenDX. I apprec
56.
Better Science of Viral Marketing: Part 2(datacommunitydc.org)
2 points by adolgert 14y ago|0 comments
57.
by adolgert 14y ago
Reproduction of work sometimes goes by the name "provenance." 1. Record what you want to do. 2. Record how, when, where, by whom it was done. 3. Include ability to run it again. (Exact reproduction is understood to be impossible given every
58.
by adolgert 14y ago
I like that explanation, coming from the data side. I wonder if the article's author is working with data or a model for the data. There is a general rule that, especially for high-dimensional models, only a few parameters are important bec
59.
by adolgert 15y ago
Carter's papers on the subject: Ballester, P. J., & Carter, J. N. (2006). Characterising the parameter space of a highly nonlinear inverse problem. Inverse Problems in Science and Engineering, 14(2), 171-191. doi:10.1080/17415970500258
60.
by adolgert 15y ago
This article raises interesting questions. He has done low-level tests which do not read much from the data or instruction pipelines, so these tests show compiled MSIL can be better optimized than C++. C++ is prone to accidental performance

More ›