## Data, Datum

February 13, 2014
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Ce soir, je quitte ma cabane d’ermite pour intervenir dans la conférence Big Data: Big Brother organisé au Cœur des Sciences, où un peu plus de trois cent personnes se sont inscrites en quelques heures. On va parler de data. Et depuis, je me ...

## loess explained in a GIF

February 13, 2014
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Local regression (loess) is one of the statistical procedures I most use. Here is a movie showing how it works

## Hat tip to the Times editors

February 13, 2014
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While I wasn't happy with how the New York Times business page covered the recent unemployment report (link), I was pleasantly surprised to see this editorial today titled "Making College Pay". Here are the key sentences: The recent jobless rate for college graduates ages 25 and older was 3.2 percent, and their median pay at full-time, full-year jobs was \$75,300 for men and \$53,700 for women. That is a far…

## R: Animating 2D and 3D plots

February 13, 2014
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One great package in R is the animation made by Yihui Xie. And just for fun, we are going to explore that. Our aim is to create simple animated 2D and 3D plots. Here is the first one, 2D of courseThe code,It's a piece of cake right? The function we use...

## Stopping rules and Bayesian analysis

February 13, 2014
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I happened to receive two questions about stopping rules on the same day. First, from Tom Cunningham: I’ve been arguing with my colleagues about whether the stopping rule is relevant (a presenter disclosed that he went out to collect more data because the first experiment didn’t get significant results) — and I believe you have […]The post Stopping rules and Bayesian analysis appeared first on Statistical Modeling, Causal Inference, and…

## A message worth repeating

February 13, 2014
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When you see two time series, resist the temptation to plot them as lines on the same chart. According to the Atlantic, the following dual-axis chart has been making the rounds in the investment community: (thanks to Alberto Cairo for...

## Registration for the 2014 ‘R in Insurance’ conference has opened

February 13, 2014
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The registration for the second conference on R in Insurance on Monday 14 July 2014 at Cass Business School in London has opened. This one-day conference will focus again on applications in insurance and actuarial science that use R, the lingua franca ...

## A Significantly Improved Significance Test. Not!

February 13, 2014
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It is my great pleasure to share with you a breakthrough in statistical computing. There are many statistical tests: the t-test, the chi-squared test, the ANOVA, etc. I here present a new test, a test that answers the question researchers are most an...

## Bayesian Model Selection – A Worked Example

February 12, 2014
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Choosing between non-nested models can be challenging. A lot of statisticians and econometricians find that a Bayesian approach has a lot to offer when it comes to addressing this challenge. I'm certainly of that view myself.Let me take you through an ...

## Bayes factor t tests, part 1

February 12, 2014
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In my first post, I described the general logic of Bayes factors. I will continue discussing the general logic of Bayes factor, while introducing some of the basic functionality of the BayesFactor package.Recap: What is a Bayes factor?The Bayes factor is the relative evidence provided by the data for comparing two statistical models. It has two equivalent definitions:The Bayes factor is the relative predictive success between two hypotheses: it is…

## Temperatures Series as Random Walks

February 12, 2014
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Last year, I did mention in a post that unit-root tests are dangerous, because they might lead us to strange models. For instance, in a post, I did obtain that the temperature observed in January 2013, in Montréal, might be considered as a random walk process (or at leat an integrated process). The code to extract the data has changed (since the website has been updated), so here, we use…

## Unit Root Tests

February 12, 2014
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$(Y_t)$

This week, in the MAT8181 Time Series course, we’ve discussed unit root tests. According to Wold’s theorem, if is  (weakly) stationnary then where is the innovation process, and where  is some deterministic series (just to get a result as general as possible). Observe that as discussed in a previous post. To go one step further, there is also the Beveridge-Nelson decomposition : an integrated of order one process, defined as…

## 123456789

February 12, 2014
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Every year the magazine Science and the National Science Foundation choose the best visualizations from Science and Engineering. The winners of …Continue reading →

## 123456789

February 12, 2014
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Every year the magazine Science and the National Science Foundation choose the best visualizations from Science and Engineering. The winners of …Continue reading →

## How to think about “identifiability” in Bayesian inference?

February 12, 2014
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We had some questions on the Stan list regarding identification. The topic arose because people were fitting models with improper posterior distributions, the kind of model where there’s a ridge in the likelihood and the parameters are not otherwise constrained. I tried to help by writing something on Bayesian identifiability for the Stan list. Then […]The post How to think about “identifiability” in Bayesian inference? appeared first on Statistical Modeling,…

## Fundamental theorems of mathematics and statistics

February 12, 2014
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Although I currently work as a statistician, my original training was in mathematics. In many mathematical fields there is a result that is so profound that it earns the name "The Fundamental Theorem of [Topic Area]." A fundamental theorem is a deep (often surprising) result that connects two or more [...]

## Fathom Design Creates Infographic PDF Posters from Nike+ FuelBand Data

February 12, 2014
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Fathom Design, lead by visualization design pioneer Ben Fry, just released Year in Nike Fuel [yearinnikefuel.com]. Based on Nike's public developer APIs, the posters allow various kinds of patterns to be recognized, as the working dad, the mountaineer...

## Hierarchical forecasting with hts v4.0

February 12, 2014
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A new version of my hts package for R is now on CRAN. It was completely re-written from scratch. Not a single line of code survived. There are some minor syntax changes, but the biggest change is speed and scope. This version is many times faster than the previous version and can handle hundreds of thousands of time series without complaining. The speed-up is due to some new research I…

February 12, 2014
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These are questions I answered recently for an undergrad who had questions about how best to prepare herself for graduate school. I thought the answers might be more widely of interest, and with a lot of editing, am including the questions and answers ...

## Circular Binning Map Highlights Enjoyable U.S. Weather Conditions

February 11, 2014
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Binning is a clever method to avoid overlapping data points by aggregating multiple points in a grid of polygons, and using color to denote the relative density (see some interesting explanations here and here). The map The Pleasant Places to Live [k...

## A million ways to connect R and Excel

February 11, 2014
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In quantitative finance both R and Excel are the basis tools for any type of analysis. Whenever one has to use Excel in conjunction with R, there are many ways to approach the problem and many solutions. It depends on what you really want to do and the size of the dataset you’re dealing with. I […]

## There is no Such Thing as Biomedical "Big Data"

February 11, 2014
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At the moment, the world is obsessed with “Big Data” yet it sometimes seems that people who use this phrase don’t have a good grasp of its meaning.  Like most good buzz-words, “Big Data” sparks the idea of something grand and complicated...

## An Interview With Bradley Efron

February 11, 2014
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You've all heard about the bootstrap, and you all know that it was Bradley Efron (Statistics, Stanford) who came up with the idea. (If I'm wrong, you can check this earlier post.)On Twitter yesterday, Joe Blitzstein (Statistics, Harvard; @stat110)...