November 25, 2014

6:00 AM | Thin folding
I have another new preprint on arXiv this evening: Folding a Paper Strip to Minimize Thickness, arXiv:1411.6371, with six other authors (Demaine, Hesterberg, Ito, Lubiw, Uehara, and Uno); it's been accepted at WALCOM.The basic goal of this is to try to understand how to measure the thickness of a piece of paper that has been folded into a shape that lies flat in the plane. For instance, in designing origami pieces, it's undesirable to have too much thickness, both because it wastes paper […]

November 24, 2014

11:14 PM | prayers and chi-square
One study I spotted in Richard Dawkins’ The God delusion this summer by the lake is a study of the (im)possible impact of prayer over patient’s recovery. As a coincidence, my daughter got this problem in her statistics class of last week (my translation): 1802 patients in 6 US hospitals have been divided into three […]
3:36 PM | The hype cycle starts again
Completely uncritical press coverage of a speculative analysis. But, hey, it was published in the prestigious Proceedings of the National Academy of Sciences (PPNAS)! What could possibly go wrong? Here’s what Erik Larsen writes: In a paper published in the Proceedings of the National Academy of Sciences, People search for meaning when they approach a […] The post The hype cycle starts again appeared first on Statistical Modeling, Causal Inference, and Social Science.
3:14 PM | Ebola Crisis Hackathon
The Ebola Virus has killed almost 6000 people in West Africa since Dec 2013Ebola has infected over 15000 people in West Africa since the start of the current outbreak in December 2013. The disease has an estimated case fatality rate of about 71%, and efforts to control the outbreak have been hampered by the political and economic situations in the countries affected (so far almost all cases have occurred in Liberia, Sierra Leone and Guinea). Problems have included, but are certainly not limited […]
2:00 PM | On deck this week
Mon: The hype cycle starts again Tues: I (almost and inadvertently) followed Dan Kahan’s principles in my class today, and that was a good thing (would’ve even been more of a good thing had I realized what I was doing and done it better, but I think I will do better in the future, which […] The post On deck this week appeared first on Statistical Modeling, Causal Inference, and Social Science.
1:51 PM | Alexandre Grothendieck 1928–2014
Here’s a small collection of links to articles about Alexandre Grothendieck, French/German mathematician and algebraic geometer, who died on Wednesday 13 November aged 86. He was a pioneer in the field, and has been described as ‘the greatest mathematician of the 20th century’. His obituary in The Telegraph The AMS announcement A New York Times obituary An obituary at Liberation and another obituary... Read more »
12:18 PM | P-values and power in statistical tests
Today I’m going to do my best to explain Andrew Gelman’s recent intriguing post on his blog for the sake of non-statisticians including myself (hat tip Catalina Bertani). If you are a statistician, and especially if you are Andrew Gelman, please do correct me if I get anything wrong. Here’s his post, which more or […]
10:35 AM | What is a proof, really?
What is a mathematical proof? Way back when I was a college freshman, I could give you a precise answer: A proof of a statement S is a finite sequence of assertions S(1), S(2), … S(n) such that S(n) = S and each S(i) is either an axiom or else follows from one or more […]
10:15 AM | Helicobacter pylori and stem cells in the gastric crypt
Last Friday, the 4th Integrated Mathematical Oncology Workshop finished here at Moffitt. The event drew a variety of internal and external participants — you can see a blurry photo of many of them above — and was structured as a competition between four teams specializing in four different domains: Microbiome, Hepatitis C, Human papillomavirus, and […]

Houghton, J., Stoicov, C., Nomura, S., Rogers, A.B., Carlson, J., Li, H., Cai, X., Fox, J.G., Goldenring, J.R. & Wang, T.C. & (2004). Gastric cancer originating from bone marrow-derived cells., Science, 306 (5701) 1568-71. PMID:

2:34 AM | What do Rick Santorum and Andrew Cuomo have in common?
Besides family values, that is? Both these politicians seem to have a problem with the National Weather Service: The Senator: Santorum also accused the weather service’s National Hurricane Center of flubbing its forecasts for Hurricane Katrina’s initial landfall in Florida, despite the days of all-too-prescient warnings the agency had given that the storm would subsequently […] The post What do Rick Santorum and Andrew Cuomo have in common? appeared first on Statistical […]
12:51 AM | 254A, Notes 1: Elementary multiplicative number theory
In analytic number theory, an arithmetic function is simply a function from the natural numbers to the real or complex numbers. (One occasionally also considers arithmetic functions taking values in more general rings than or , as in this previous blog post, but we will restrict attention here to the classical situation of real or […]

November 23, 2014

11:14 PM | an ABC experiment
  In a cross-validated forum exchange, I used the code below to illustrate the working of an ABC algorithm: Hence I used the median and the mad as my summary statistics. And the outcome is rather surprising, for two reasons: the first one is that the posterior on the mean μ is much wider than […]
11:03 PM | Integral Octonions (Part 9)
Learn about using integral octonions and the E8 lattice to construct the Leech lattice.
10:00 PM | Links for November 23
Mona Chalabi and Andrew Flowers figure out the most common name in America, using some data by Lee Hartman to correct for the fact that first name and last name are not independent, but tend to cluster based on ethnicity. … Continue reading →
9:28 PM | A brief history of video game graphics
Part 1: Pixel PioneersPart 2: Sprite SupremePart 3: Polygon RealmPart 4: Voodoo BloomPart 5: Future Crisis
8:58 PM | My Blog is Still under Attack
Recently I wrote that my blog is under attack by spam comments. Most of the comments were caught by my spam-filter Akismet, the best-known filter for WordPress. I was receiving about 50,000 comments a day and 200 of them were sneaking through this filter. I had to moderate those and delete them. This was an […]
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 […]
2:53 PM | Princeton Abandons Grade Deflation Plan . . .
. . . and Kaiser Fung is unhappy. In a post entitled, “Princeton’s loss of nerve,” Kaiser writes: This development is highly regrettable, and a failure of leadership. (The new policy leaves it to individual departments to do whatever they want.) The recent Alumni publication has two articles about this topic, one penned by President […] The post Princeton Abandons Grade Deflation Plan . . . appeared first on Statistical Modeling, Causal Inference, and Social Science.
2:00 PM | The Math Geek Holiday Gift Guide
Looking for a gift that says, “Hey, I know you like math”? Look no further. There is an embarrassment of riches when it comes to wonderful mathematical things to give to people, but here are some of... -- Read more on
1:16 PM | Christmas Presents for Herrrr…
I believe that after my last post about ideas for Christmas gifts, you would expect this post immediately. With no further introduction, here are some of my favorite gift ideas for HeRRrrr: 1. Jewelry - I personally always like a good … Continue reading →

November 22, 2014

11:14 PM | Challis Lectures
  I had a great time during this short visit in the Department of Statistics, University of Florida, Gainesville. First, it was a major honour to be the 2014 recipient of the George H. Challis Award and I considerably enjoyed delivering my lectures on mixtures and on ABC with random forests, And chatting with members […]
10:41 PM | A temperature puzzle
Last Friday morning (the 14th) it was unseasonably cold in Atlanta. On the way to work I noticed my car’s display giving the following temperature readings: 28, 30, 32, 34, 36 – all in Fahrenheit. It somehow knew to avoid … Continue reading →
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