## Plot the conditional distribution of the response in a linear regression model

September 10, 2015
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A friend who teaches courses about statistical regression asked me how to create a graph in SAS that illustrates an important concept: the conditional distribution of the response variable. The basic idea is to draw a scatter plot with a regression line, then overlay several probability distributions along the line, […] The post Plot the conditional distribution of the response in a linear regression model appeared first on The DO…

## Some thoughts on Economics, Mathematics, Econometrics, Statistics, Machine Learning, etc

September 10, 2015
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$(\boldsymbol{x}_i,y_i)$

There were a lot of posts, recently, related to those topics, starting with Noah Smith ‘s piece entitled “Economics has a Math Problem” and more recently “Econometrics, Math, and Machine Learning…what?” by Matt Bogard. I don’t have (yet) a clear mind on those issues, but there are still a few thoughts that I wanted to share. I did not really want to, but I’ve been asked, on Twitter, and I thought it might be good…

## Le Monde puzzle [#928]

September 9, 2015
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A combinatorics Le Monde mathematical puzzle: How many distinct integers between 0 and 16 can one pick so that all positive differences are distinct? If k is the number of distinct integers, the number of positive differences is 1+2+…+(k-1) = k(k-1)/2, which cannot exceed 16, because it is a subset of {1,2,…,16}, meaning k cannot […]

## Le Monde puzzle [#928]

September 9, 2015
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A combinatorics Le Monde mathematical puzzle: How many distinct integers between 0 and 16 can one pick so that all positive differences are distinct? If k is the number of distinct integers, the number of positive differences is 1+2+…+(k-1) = k(k-1)/2, which cannot exceed 16, because it is a subset of {1,2,…,16}, meaning k cannot […]

September 9, 2015
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I'm compiling a portfolio about the BayesFactor software, and I would love to have short comments (a few sentences to a paragraph) from people who have found the software useful. If you have used the software and you wouldn't mind sending me a short bl...

## Reproducibility is hard

September 9, 2015
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Reproducibility is hard. It will probably always be hard, because it’s hard keeping things organized. I recently had a paper accepted at G3, concerning a huge set of sample mix-ups in a large eQTL study. I’d discovered and worked out the issue back in December, 2010. I gave a talk about it at the Mouse […]

## Reproducibility is hard

September 9, 2015
By

Reproducibility is hard. It will probably always be hard, because it’s hard keeping things organized. I recently had a paper accepted at G3, concerning a huge set of sample mix-ups in a large eQTL study. I’d discovered and worked out the issue back in December, 2010. I gave a talk about it at the Mouse […]

## Home alone

September 9, 2015
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As Marta is heading to a conference, XY and I will spend a couple of days at home alone. Hopefully that won't end up like in the picture here...

## Irwin Shaw: “I might mistrust intellectuals, but I’d mistrust nonintellectuals even more.”

September 9, 2015
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A few weeks ago I picked up a paperback of stories by Irwin Shaw, printed in the late 1950s. I love these little pocket books—but this one was a bit too disposable: after about 50 pages the spine gave out and the pages started to fall out, which was a bit irritating because then I […] The post Irwin Shaw: “I might mistrust intellectuals, but I’d mistrust nonintellectuals even more.”…

## Rethinking the index data, with modesty and clarity in mind

September 9, 2015
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I discussed the rose chart used in the Environmental Performance Index (EPI) report last week. This type of data is always challenging to visualize. One should start with an objective. If the goal is a data dump, that is to...

## No one in Gene Woolsey’s class made spelling errors

September 9, 2015
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I wished I had a chance to take Gene Woolsey's class. Woolsey was a major personality in Operations Research, and from reading a set of remembrances in ORMS Today (June 2015), I learned that he was also an amazing teacher. And no one in his class made spelling errors! How cool is that. Well, I don't know if no one ever made a spelling error but I bet that the…

## debunking a (minor and personal) myth

September 9, 2015
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For quite a while, I entertained the idea that Beta and Dirichlet proposals  were more adequate than (log-)normal random walks proposals for parameters on (0,1) and simplicia (simplices, simplexes), respectively, when running an MCMC. For instance, for p in (0,1) the value of the Markov chain at time t-1, the proposal at time t could […]

## debunking a (minor and personal) myth

September 9, 2015
By

For quite a while, I entertained the idea that Beta and Dirichlet proposals  were more adequate than (log-)normal random walks proposals for parameters on (0,1) and simplicia (simplices, simplexes), respectively, when running an MCMC. For instance, for p in (0,1) the value of the Markov chain at time t-1, the proposal at time t could […]

## Recipe for Centered Horizontal Stacked Barplots (Useful for Likert scale responses)

September 8, 2015
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There is a nice package and paper about this here: http://www.jstatsoft.org/v57/i05/paper. However, the associated code is complex and uses lattice. Here's a brief recipe using base graphics that implements the above figure: set.seed(40) x

## Statbusters: Were you drunk on Labor Day?

September 8, 2015
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On Labor Day, our new Statbusters column appeared. This one concerns a popular news story from some weeks ago, saying science has proven that there are four types of drunks. The four refers to four "clusters" formed by running a cluster analysis algorithm. But four is decided by the analyst. Some algorithms won't run unless the analyst specifies the number of clusters; other algorithms generate the best structure for every…

## “Dow 36,000” guy offers an opinion on Tom Brady’s balls. The rest of us are supposed to listen?

September 8, 2015
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Football season is returning so it’s time for us to return to that favorite statistical topic from the past football season: Tom Brady’s deflated balls. Back in June, Jonathan Falk pointed me to this report. You can click through if you’d like and take a look. I didn’t bother reading it because it had no […] The post “Dow 36,000” guy offers an opinion on Tom Brady’s balls. The rest…

## Find the ODS table names produced by any SAS procedure

September 8, 2015
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Statistical programmers often have to use the results from one SAS procedure as the input to another SAS procedure. Because ODS enables you to you to create a SAS data set from any ODS table or graph, it is easy to obtain a data set that contains the value of […] The post Find the ODS table names produced by any SAS procedure appeared first on The DO Loop.

## Matlab/Octave and Python demos for BDA3

September 7, 2015
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My Bayesian Data Analysis course at Aalto University started today with a record number of 84 registered students! In my course I have used some Matlab/Octave demos for several years. This summer Tuomas Sivula translated most of them to Python and Python notebook. Both Matlab/Octave and Python demos are now available at Github in hope they […] The post Matlab/Octave and Python demos for BDA3 appeared first on Statistical Modeling, Causal…

## How do you know if your model is going to work? Part 2: In-training set measures

September 7, 2015
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Authors: John Mount (more articles) and Nina Zumel (more articles). When fitting and selecting models in a data science project, how do you know that your final model is good? And how sure are you that it’s better than the models that you rejected? In this Part 2 of our four part mini-series “How do … Continue reading How do you know if your model is going to work? Part…

## BEA to Resume Provision of NSA GDP

September 7, 2015
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In an earlier post, I argued for publication of non-seasonally-adjusted (NSA) series. Thanks to a helpful communication from Jonathan Wright, I recently learned (as did he) that BEA will resume compilation and publication of NSA U.S. GDP...

## College redux

September 7, 2015
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What's all this talk about Bayesian Inference the kids are spreading on Snapchat? You too can get in on the conversation. Learning modern statistics made fun and easy! Brought to you by Dataman.

## Comments on Imbens and Rubin causal inference book

September 7, 2015
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Guido Imbens and Don Rubin recently came out with a book on causal inference. The book’s great (of course I would say that, as I’ve collaborated with both authors) and it’s so popular that I keep having to get new copies because people keep borrowing my copy and not returning it. Imbens and Rubin come […] The post Comments on Imbens and Rubin causal inference book appeared first on Statistical…

## On deck this week

September 7, 2015
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Mon: Comments on Imbens and Rubin causal inference book Tues: “Dow 36,000″ guy offers an opinion on Tom Brady’s balls. The rest of us are supposed to listen? Wed: Irwin Shaw: “I might mistrust intellectuals, but I’d mistrust nonintellectuals even more.” Thurs: Death of a statistician Fri: Being polite vs. saying what we really think […] The post On deck this week appeared first on Statistical Modeling, Causal Inference, and…