Posts

November 23, 2014

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6:10 PM | How medieval astronomers made trig tables
How would you create a table of trig functions without calculators or calculus? It’s not too hard to create a table of sines at multiples of 3°. You can use the sum-angle formula for sines sin(α+β) = sin α cos β + sin β cos α. to bootstrap your way from known values to other […]
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4:54 PM | Accuracy of Generated Fractals
Note: I refer to the Mandelbrot set in general as the M-set for short. When I was writing the post on Rough Mandelbrot Sets I tried out some variations on the rough set. One variation was to measure the generated … Continue reading →

November 22, 2014

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9:06 PM | Link o' the day: How I start—Haskell
Chris Allen has a very good walk-through for starting Haskell programmers (and for projects using cabal): How I Start: Haskell. (Hey, wha'da'ya' want? It's NaNoWriMo and I'm way behind. And busy.)
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4:41 PM | Sunday Morning Insight: It's Complicated...On Games, NP-hardness, Grothendieck, Learning and Friends.
At the last Machine Learning meetup in Paris, someone (I believe it was Vincent Guigue ) made the comment that "not" was a relatively powerful feature for detecting sentiment analysis in a written paragraph. Some of us wondered if the same was really true in French (it does not look like it is). Clearly it opens another line of thought, if you have a model that works well in English, because it has been able to put the right importance on the "not" feature, will that model be as efficient […]
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3:12 PM | Ergodic
Roughly speaking, an ergodic system is one that mixes well. You get the same result whether you average its values over time or over space. This morning I ran across the etymology of the word: In the late 1800s, the physicist Ludwig Boltzmann needed a word to express the idea that if you took an […]
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6:33 AM | Officejet
Home office upgrade: our laser colour printer, Canon i-SENSYS LBP5050n was bought in summer 2009, more than 5 years ago. It had its fair share of driver problems, and connection problems in the home LAN. Recently the connection has mostly worked … Continue reading →
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6:00 AM | Saturday Morning Videos: Machine Learning Summer School, Iceland 2014
Here are all 41 hours of courses given in Iceland this Summer at the Machine Learning Summer School. Enjoy the rest fo your week-end. I know...you're welcome.Introduction to Machine Learning -- Neil Lawrence (Part 1) MLSS Iceland 2014 1:13:30    What is Machine Learning: A Probabilistic Perspective -- Neil Lawrence (Part 2) MLSS Iceland 2014 1:30:31    Deep Learning -- Yoshua Bengio (Part 1) MLSS Iceland 2014 1:28:22    Deep Learning -- Yoshua Bengio (Part […]

November 21, 2014

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3:12 PM | CKN: Convolutional Kernel Networks - implementation -
You probably recall this entry on Deep Learning and Convolutional Kernel Networks, well there is an attendant implementation available now. From the project page: AboutWhat is CKN?CKN (Convolutional Kernel Networks) is a software package corresponding to the NIPS paper ``Convolutional Kernel Networks''. LicenseVersion 1.0 and later are open-source under licence GPLv3. Related publications J. Mairal, P. Koniusz, Z. Harchaoui and C. Schmid. Convolutional Kernel Networks. Advances in Neural […]
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2:45 PM | #AcWriMo progress report, 2/3 of way through
We’re in the homestretch now for #AcWriMo 2014! It’s hard to believe there are less than 10 days left in this madwriting frenzy. I’ve made some really good progress on my first goal (revising my grant proposal) since I last posted an update on my progress. I’ve spent much of my writing time writing code instead of […]
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9:03 AM | Provable Bounds for Learning Some Deep Representations
Following up on this entry, here are some headways connecting the deep architectures of some neural networks with random matrix theory and some of the findings in compressive sensing. From the paper:In fact our result that a single layer of our generative model is a sparse denoising autoencoder can be seen as an analog of the fact that random matrices are good for compressed sensing/sparse reconstruction (see Donoho (Donoho,2006) for general matrices and Berinde et al. (Berinde et al., 2008) […]
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8:17 AM | PyQtConfig: A simple API for keeping your PyQt Widgets and config in sync
Introducing PyQtConfig: a simple API for handling, persisting and synchronising configuration within PyQt applications. This module was built initially as part of the Pathomx data analysis platform but spun out into a standalone module when it became clear it was quite useful. This post gives a brief overview of the API features and use. It is still in development so suggestions, comments, bug reports and pull-requests are very welcome. Features consistent interface to read values […]
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5:09 AM | Open access, ACM and the Gates Foundation.
Matt Cutts, in an article on the new Gates Foundation open access policy (ht +Fernando Pereira) says thatwhile the ACM continues to drag its heels, the Gates Foundation has made a big move to encourage Open Access...Which got me thinking. Why can't the ACM use this policy as a guidelines to encourage open access ? Specifically,Announce that from now on, it will subsidize/support the open access fees paid by ACM members(partially) eat the cost of publication in ACM publications […]

November 20, 2014

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9:05 PM | Estimate bicycle flows with agent-based simulation
Knowing when and where how many people cycle would be valuable for many questions associated with bicycle research, planning and promotion. As I’ve already noted on several occasions, the data availability and quality is generally very poor in this context. For motorized traffic and public transportation networks, a whole lot of different traffic models and extensive […]
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3:30 PM | Nonlinear Information-Theoretic Compressive Measurement Design
Compressive sensing, nonlinearity, classification, terrific !Nonlinear Information-Theoretic Compressive Measurement Design by Liming Wang, Abolfazl Razi, Miguel Rodrigues, Robert Calderbank, Lawrence Carin We investigate design of general nonlinear functions for mapping high-dimensional data into a lower-dimensional (compressive) space. The nonlinear measurements are assumed contaminated by additive Gaussian noise. Depending on the application, we are either interested in recovering the […]
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6:00 AM | Riemannian Pursuit for Big Matrix Recovery
Greedy algorithm for nuclear norm minimization on the manifold (hopefully we'll get to see an implementation of it at some point in time)Riemannian Pursuit for Big Matrix Recovery by Mingkui Tan, Ivor W. Tsang, Li Wang, Jialin Pan, Bart Vandereycken Low rank matrix recovery is a fundamental task in many real-world applications. The performance of existing methods, however, deteriorates significantly when applied to ill-conditioned or large-scale matrices. In this paper, we therefore […]
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3:26 AM | Two Versus Three
The role of 2 and 3 in mathematics Electrika source Margaret Farrar was the first crossword puzzle editor for The New York Times. Ken fondly recalls seeing her name while watching his father do the daily and weekly NYT puzzles—they were under Farrar’s byline as editor until 1969 when she retired from the Times. More […]

November 19, 2014

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5:29 PM | Sparse Reinforcement Learning via Convex Optimization
How do you learn policies when you have too many features ?Sparse Reinforcement Learning via Convex Optimization Zhiwei Qin, Weichang Li We propose two new algorithms for the sparse reinforcement learning problem based on different formulations. The first algorithm is an off-line method based on the alternating direction method of multipliers for solving a constrained formulation that explicitly controls the projected Bellman residual. The second algorithm is an online stochastic approximation […]
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1:00 PM | Miscellaneous math notes
This web site started as static HTML files. Later I added a WordPress blog, but still wrote some things as static HTML pages for various reasons. Now I’ve moved most of those static pages to WordPress pages so that they’ll have the same style as the blog. There’s not a good way to find these […]
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7:17 AM | Tested In-Depth: Apple iPad Air 2
No summary available for this post.
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6:00 AM | How to Scale Up Kernel Methods to Be As Good As Deep Neural Nets
How to Scale Up Kernel Methods to Be As Good As Deep Neural Nets by Zhiyun Lu, Avner May, Kuan Liu, Alireza Bagheri Garakani, Dong Guo, Aurélien Bellet, Linxi Fan, Michael Collins, Brian Kingsbury, Michael Picheny, Fei Sha In this paper, we investigate how to scale up kernel methods to take on large-scale problems, on which deep neural networks have been prevailing. To this end, we leverage existing techniques and develop new ones. These techniques include approximating kernel functions […]

November 18, 2014

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9:40 PM | Computing research
There is nothing to do with computers that merits a PhD. Max Newman (1897-1984), as quoted in Alan Turing: The Enigma by Andrew Hodges  Filed under: Computer science, Research
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9:36 PM | Tested: The Show — Cooking with Cricket Flour
No summary available for this post.
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9:27 PM | Googol and googolplex
Numericon gives the history of the words googol and googolplex: … the famous googol, 10100 (a 1 followed by 100 zeros), defined in 1929 by American mathematician Edward Kasner and named by his nine-year-old nephew, Milton Sirotta. Milton went even further and came up with the googolplex, now defined as 10googol but initially defined by […]
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9:10 PM | Gremlins in the Machine: Creating custom tools for the Pathomx data analysis platform
Pathomx is a workflow-based data analysis tool built on IPython. It began as a metabolomic-analysis toolkit, but has extended to support general data analysis workflows. It aims to be simple to use for non-experts while powerful enough for complex analysis tasks. Key to both of these goals is the ability to create ‘custom tools’ that can be drag-dropped together to form larger workflows. Previously custom tool creation required a developer installation, however with the […]
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8:50 PM | La tête dans les étoiles
Le MOOC "Introduction à l'Astrophysique" de l'EPFL Je voulais depuis longtemps suivre un MOOC, pour voir à quoi ça ressemble. Voyant que le Laboratoire d'astrophysique de l'EPFL propose le premier cours d'introduction à l'astrophysique en français sur edX, je me suis immédiatement inscrit et je le suis assidûment depuis deux mois en y consacrant une bonne soirée par semaine.
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8:00 PM | The Best Digital Kitchen Scale Today
This post was done in partnership with The Sweethome, a list of the best gear for your home.Read the full article atTheSweethome.comIf you need an all-purpose digital kitchen scale for baking, cooking by ratio, or even measuring beans to brew coffee, the Jennings CJ4000 ($26) combines some of the best features we’ve seen in a scale. It’s easy to use and store, comes with an AC adapter to save on batteries, and you can disable the auto-off function—so you can take your sweet […]
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7:00 PM | Making of Benedict Cumberbatch's Wax Statue
No summary available for this post.
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3:25 PM | A Randomized Algorithm for CCA
A Randomized Algorithm for CCA by Paul Mineiro, Nikos Karampatziakis We present RandomizedCCA, a randomized algorithm for computing canonical analysis, suitable for large datasets stored either out of core or on a distributed file system. Accurate results can be obtained in as few as two data passes, which is relevant for distributed processing frameworks in which iteration is expensive (e.g., Hadoop). The strategy also provides an excellent initializer for standard iterative solutions. h/t […]
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3:00 PM | Thomas Richner's Cardbard Millennium Falcon Model
Several of you sent this link our way, and it definitely deserves the love. Thomas Richner, an Associate Professor at Columbus College of Art and Design, spent two months building a large scale replica of the Millennium Falcon out of excess cardboard found in his basement. According to his build log, the goal of the two-month project was to replicate the five-foot shooting model of the Falcon used in Episode IV, with as much detail as possible. Greeblie placement took the most work, and details […]
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2:00 PM | Interstellar SPOILERCAST - 11/18/2014
Adam, Norm, and Will have mixed feeling about Interstellar, Christopher Nolan's latest project. Rest assured of one thing though, there will be spoilers aplenty. Enjoy!
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