# Monthly Archives: August 2011

## Bayes factors and martingales

August 10, 2011
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$Bayes factors and martingales$

A surprising paper came out in the last issue of Statistical Science, linking martingales and Bayes factors. In the historical part, the authors (Shafer, Shen, Vereshchagin and Vovk) recall that martingales were popularised by Martin-Löf, who is also influential in the theory of algorithmic randomness. A property of test martingales (i.e., martingales that are non

## SNA: Visualising an email box with R

August 10, 2011
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Are statistics sexy? Visualising social networks certainly is! I wrote a little function, which makes producing beautiful plots depicting a mailbox with R an extremely easy task. I find visualisations of ‘social graphs’ particularly appealing. They look like flowers. I … Continue reading

## Dump MySQL to CSV using R

August 10, 2011
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Based on a related post on one of my favorite python-lists I remembered, that I wrote a similar snipplet some time ago. So if you want to dump your whole MySQL database to csv-files you can recycle the following code: ?Download mysql2cvs.R1 2 3 4 5 6 7 8 9 require(RMySQL) m<-MySQL() summary(m) con<-dbConnect(m, dbname

## Using the google prediction API from R

August 10, 2011
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Google has a "black box" prediction API that they provide for use with creating recommender systems or filtering spam. Furthermore, they provide an R package for interfacing that API, but try as I might I cannot get it to work under windows. Here are ...

## Plotting molecular properties for (sub)sets

August 10, 2011
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For a toxicology paper we are writing up, I need to create a few plots showing how the toxic and non-toxic molecules differ (or not) with respect to a few molecular properties, such as logP or the molecular weight. The rcdk package provides all, of cou...

## A 60-second survey for R users

August 10, 2011
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I'm doing a little research to validate estimates of the size of the R user community. If you're an R user, please take a minute to complete this three-question survey on R usage at your organization. Thanks in advance. Revolution Analytics: R user base survey

## Informational Easing: A Change In F.O.M.C. Expectations

August 10, 2011
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Let's analyze the latest FOMC policy move.The FOMC met yesterday and changed up the communications strategy.  How so? Well, until yesterday the statement has been saying as of June 22, 2011:"The Committee continues to anticipat...

## Scraping web data in R

August 10, 2011
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In my last post, I went through a lot of effort to scrape the PMI index off the ISM website.  It turns out that was unnecessary effort, as commentator "senne" pointed out that this index is available from FRED, with the symbol NAPM. &nbs...

## Using a “pure infographic” to explore differences between information visualization and statistical graphics

August 10, 2011
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Our discussion on data visualization continues. One one side are three statisticians–Antony Unwin, Kaiser Fung, and myself. We have been writing about the different goals served by information visualization and statistical graphics. On the other side are graphics experts (sorry for the imprecision, I don’t know exactly what these people do in their day jobs