Publications by andrew
Comment of the week
This one, from DominikM: Really great, the simple random intercept – random slope mixed model I did yesterday now runs at least an order of magnitude faster after installing RStan 2.3 this morning. You are doing an awesome job, thanks a lot! The post Comment of the week appeared first on Statistical Modeling, Causal Inference, and Social Scienc...
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Stan goes to the World Cup
I thought it would be fun to fit a simple model in Stan to estimate the abilities of the teams in the World Cup, then I could post everything here on the blog, the whole story of the analysis from beginning to end, showing the results of spending a couple hours on a data analysis. It didn’t work so well, but I guess that’s part of the story t...
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Comrades Marathon: A Race for Geriatrics?
It has been suggested that the average Comrades Marathon runner is gradually getting older. As an “average runner” myself, I will not deny that I am personally getting older. But, what I really mean is that the average age of all runners taking part in this great event is gradually increasing. This is not just an idle hypothesis: it is suppor...
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Commitments of Traders: Moves in the Last Week
In my previous post I gave some background information on the Commitments of Traders report along with a selection of summary plots. One of the more interesting pieces of information that one can glean from these reports is the shift in trading sentiment from week to week. Below is a plot reflecting the relative change in the number of long and s...
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Plotting Flows with riverplot
I have been looking for an intuitive way to plot flows or connections between states in a process. An obvious choice is a Sankey Plot, but I could not find a satisfactory implementation in R… until I read the riverplot post by January Weiner. His riverplot package does precisely what I am need. Getting your data into the right format is a sligh...
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What does CNN have in common with Carmen Reinhart, Kenneth Rogoff, and Richard Tol: They all made foolish, embarrassing errors that would never have happened had they been using R Markdown
Rachel Cunliffe shares this delight: Had the CNN team used an integrated statistical analysis and display system such as R Markdown, nobody would’ve needed to type in the numbers by hand, and the above embarrassment never would’ve occurred. And CNN should be embarrassed about this: it’s much worse than a simple typo, as it indicates they d...
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Creating More Effective Graphs
A few years ago I ordered a copy of the 2005 edition of Creating More Effective Graphs by Naomi Robbins. Somewhat shamefully I admit that the book got buried beneath a deluge of papers and other books and never received the attention it was due. Having recently discovered the R Graph Catalog, which implements many of the plots from the book using...
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Zacks Data on Quandl
Data from Zacks Research have just been made available on Quandl. Registered Quandl users have free preview access to these data, which cover the following: Earnings Estimates: forward-looking consensus forecasts; Earnings Surprises: estimated future and actual historical earnings; Earnings Announcements: predictions for earnings announcement...
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Simulating Intricate Branching Patterns with DLA
Manfred Schroeder’s book Fractals, Chaos, Power Laws is a fruitful source of interesting topics and projects. He gives a thorough description of Diffusion-Limited Aggregation (DLA) as a technique for simulating physical processes which produce intricate branching structures. Examples, as illustrated below, include Lichtenberg Figures, dielectri...
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Downloading Option Chain Data from Google Finance in R: An Update
I recently read an article which showed how to download Option Chain data from Google Finance using R. Interestingly, that article appears to be a close adaption of another article which does the same thing using Python. While playing around with the code from these articles I noticed a couple of things that might benefit from minor tweaks. Befor...
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