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# Posts

### March 01, 2014

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In January, I did a series with some heavier mathematics, involving lots of number theory, combinatorics, and some fairly difficult manipulation. Last month, we took a little rest from this by talking a bit about casino games and optimal strategies. The mathematics we used was more probability and game theory. This month, I thought we could explore something completely different that is also extremely interesting. It is taught in school (much of the material in this post actually comes straight […]
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Filed under: pictures, Travel Tagged: Canada, James Wolfe, Louis de Montcalm, parlement, Québec
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Stephen Senn writes: For many years now I [Senn] have been making the point that obtaining a license to market a drug should carry with it the obligation to share the results with interested parties. . . . Amongst those misunderstanding the issues, are many who work in the pharmaceutical industry. A common assumption is […]The post “We are moving from an era of private data and public analyses to one of public data and private analyses. Just as we have learned to be cautious about […]
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Because this blogpost covers both mountain biking and proving theorems, it is being simultaneously published by the Mathematical Association of America in my Devlin’s Angle series.  In my post last month, I described my efforts to ride a particularly difficult stretch of a local mountain bike trail in the hills just west of Palo Alto. As promised, I […]
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Scrive Virginia Wolf, durante l'incontro tra Orlando e Nick Greene, poeta, che questi e' "forse l'ultimo" a osare "arrostire il formaggio nel gran caminetto all'italiana".E qui partono i ricordi, di domeniche mattina buie e nuvolose, con il freddo e la pioggia che cade dal cielo, tutti intorno al caminetto a riscladarsi e ad arrostire salsiccia.O magari un pezzo di formaggio, quello stagionato, il caciocavallo, magari con un pezzo di pane sul ginocchio dove poi posare il formaggio prima che si […]

### February 28, 2014

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Over the past few weeks, I read Broken Blade by Kelly McCullough, the start to a series of novels taking place in a fantasy universe and involving the same characters. As in many recent novels I read, the main character Aral Kingslayer is more an anti-hero, not very congenial and rather drawn towards booze and […]
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Quantum mechanics places a fundamental limit on the accuracy of measurements. In most circumstances, the measurement uncertainty is distributed equally between pairs of complementary properties; this leads to the 'standard quantumlimit' for measurement resolution. Using a technique known as 'squeezing', it is possible to reduce the uncertainty of one desired property below the standard quantumlimit at the expense of increasing that of the complementary one. Squeezing is already being used to […]
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The story so far:  New York Times columnist Nicholas Kristof wrote a piece called “Professors, we need you!” in which he mourned the loss of the public intellectual of yonderyear: SOME of the smartest thinkers on problems at home and around the world are university professors, but most of them just don’t matter in today’s […]
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This week I've been attending the Conference on Meaningfulness and Learning Spaces at UC Irvine, in honor of the 80th birthday of my co-author Jean-Claude Falmagne. I believe videos of the talks will eventually be online and I'll put up a link to mine when that happens.Jean-Claude himself gave a talk, in which the following cute geometric fact came up as an example: If f(x, y) is the function that computes the length of the hypotenuse of a right triangle with side lengths x and y, then f obeys […]
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This is a model of a mathematical structure called a “Cantitruncated 600-cell”, colloquially known as a 4D buckyball. It took twenty people five hours to build and contains over 10,000 pieces of specialised plastic called Zometool. Such a model has never been seen in the UK before and I’m incredibly proud to have been able […]
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Filed under: pictures, Travel
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I’m in Berkeley this week, where I gave two talks (here are my slides from Monday’s talk on recommendation engines, and here are my slides from Tuesday’s talk on modeling) and I’ve been hanging out with math nerds and college friends and enjoying the amazing food and cafe scene. This is the freaking life, people. […]
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Paul Alper writes: Hi Andrew (or Andy or even Gelman [17 of them]): Go to this link and have some fun with (useless? powerful?) data mining. As the authors say, it is addictive. Paul (no other way to spell it) Alper [215 of us] I’m reminded of this discussion from 2012, “Michael’s a Republican, Susan’s […]The post Combining two of my interests appeared first on Statistical Modeling, Causal Inference, and Social Science.
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From the Onion: Modern Science Still Only Able To Predict One Upcoming Tetris Block. Foreknowledge of those shapes, she explained, could lead to a breakthrough phenomenon she described as “a perpetual Tetris” of unlimited duration. “While this remains entirely hypothetical at this moment, there exists a theoretical point at which the elimination of bottom rows […]
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Govind Manian writes: I wanted to pass along a fragment from Lichtenberg’s Waste Books — which I am finding to be great stone soup — that reminded me of God is in Every Leaf: To the wise man nothing is great and nothing small…I believe he could write treatises on keyholes that sounded as weighty […]The post God/leaf/tree appeared first on Statistical Modeling, Causal Inference, and Social Science.
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Euclidean geometry, codified around 300 BCE by Euclid of Alexandria in one of the most influential textbooks in history, is based on 23 definitions, 5 postulates, and 5 axioms, or “common... -- Read more on ScientificAmerican.com
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Enzymes play an essential role in life. Without them, the translation of genetic material into proteins — the building blocks of all phenotypic traits — would be impossible. That fact, however, poses a problem for anyone trying to understand how life appeared in the hot, chaotic, bustling molecular “soup” from which it sparked into existence […]

Bianconi, G., Zhao, K., Chen, I.A. & Nowak, M.A. (2013). Selection for replicases in protocells., PLoS Computational Biology, 9 (5) PMID:

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In the plane to Montréal, today, I read this paper by Kulkarni, Saeedi and Gershman, which will be presented at AISTATS. The main idea is to create a mix between particle Monte Carlo and a kind of quasi-Monte Carlo technique (qNC is not mentionned in the paper), using variational inference (and coordinate ascent) to optimise […]

### February 27, 2014

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There is computational statistics and there is statistical computing. And then there is statistical algorithmic. Not the same thing, by far. This 2014 book by Weihs, Mersman and Ligges, from TU Dortmund, the later being also a member of the R Core team, stands at one end of this wide spectrum of techniques required by […]
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Filed under: pictures Tagged: Eiffel Tower, Palais de Chaillot, Paris, sunset, Trocadéro
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Jason Rosenhouse is a mathematician and science blogger who has been very actively engaged in the American dispute between scientists and creationists for a number of years. Unlike many of his fellow warriors for science Jason has displayed a remarkable … Continue reading →
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Aki points us to this discussion from Rolf Zwaan: The first massive replication project in psychology has just reached completion (several others are to follow). . . . What can we learn from the ManyLabs project? The results here show the effect sizes for the replication efforts (in green and grey) as well as the […]The post “What Can we Learn from the Many Labs Replication Project?” appeared first on Statistical Modeling, Causal Inference, and Social Science.
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Can we describe reality? As a general philosophical question, I could spend all day discussing it and never arrive at a reasonable answer. However, if we restrict to the sort of models used in theoretical biology, especially to the heuristic models that dominate the field, then I think it is relatively reasonable to conclude that […]

Ohtsuki, H. & Nowak, M.A. (2006). The replicator equation on graphs., Journal of Theoretical Biology, 243 (1) 86-97. PMID:

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Here’s a strange way to do arithmetic on the real numbers. First, we’ll need to include +∞ and -∞ with the reals. We define the new addition of two elements x and y to be -log (exp(-x) + exp(-y) ).…Read more ›

### February 26, 2014

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Last week, I flew down to Montpellier for two days of work on ABC model choice with Jean-Michel Marin and Pierre Pudlo. Although we missed the COLT 2014 deadline, we are now close to completing this work that will propose a rather radical change in our advocacy of how ABC model choice should be conducted. […]
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We present a translation and analysis of an unpublished manuscript by Albert Einstein in which he proposed a 'steady-state' model of the universe. The manuscript appears to have been written in early 1931 and demonstrates that Einstein once considered a cosmic model in which the mean density of matter in an expanding universe remains constant due to a continuous creation of matter from empty space, a process he associated with the cosmological constant. This model is in marked contrast to […]
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Source Transcript Def. \begin{align} x,y \text{ proximal} & \Leftrightarrow \forall V \in \mathfrak{U}(\overbrace{\Delta}^{\text{Diag. in $X\times X$}}) \exists s \in S: (sx, sy) \in V \\ & \underbrace{\Leftrightarrow}_{\text{topologie: diese Ueberd. bilden Umg.basis von $\Delta$ in $X^2$}} \forall (U_i)_{i=1}^m, \bigcup U_i = …
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An anonymous reviewer wrote: I appreciate informal writing styles as a means of increasing accessibility. However, the informality here seems to decrease accessibility – partly because of the assumed knowledge of the reader for concepts and terms, and also for its wandering style. Many concepts are introduced without explanation and are not clearly and decisively […]The post A good comment on one of my papers appeared first on Statistical Modeling, Causal Inference, and Social […]
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This June 8 to 14, there will be a week long gathering in Snowbird, Utah for young mathematicians working on cluster algebras. The target audience here are either current graduate students, or people with Ph. D. in the last 3 or so years, who would be ready to start working on problems in cluster algebras. […]