Monthly Archives: March 2011

Grey’s Anatomy Network of Sexual Relations

March 25, 2011
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This all began with an introductory presentation about social network analysis to a group of medical students.  What better way to grab their attention than with attractive, fake doctors having sex on television?  Naturally this led to the dense network … Continue reading →

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MCMC with errors

March 25, 2011
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MCMC with errors

I received this email last week from Ian Langmore, a postdoc in Columbia: I’m looking for literature on a subject and can’t find it:  I have a Metropolis sampler where the acceptance probability is evaluated with some error.  This error is not simply error in evaluation of the target density.  It occurs due to the

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Day #11 Easter “egg”

March 25, 2011
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This is not my daily blogpost, but something I found while searching for different plots just copy this code and post it in your Rserve (or what you use to give in R commands) install.packages("onion") require(onion) data(bunny) p3d(bunny,theta=3,phi=1...

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Radiation levels at Fukushima

March 24, 2011
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Radiation levels at Fukushima

From BWR The above graph is derived from data scraped from TEPCO press releases. Every hour or so for the first few days of the crisis, a TEPCO van would record radiation (probably Beta/Gamma, but the translation is unclear) at … Continue reading →

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No simulation is complete without a gif

March 24, 2011
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No simulation is complete without a gif

I promise this is my last post on the now week and a half old π pay! Building on the last post, I figured I could show how convergence actually works in the estimation algorithm. If you’ll recall, we plotted … Continue reading →

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Predicting R models with PMML: Revolution R Enterprise and ADAPA

March 24, 2011
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The recently announced Revolution Analytics / Zementis partnership goes a long way towards demonstrating how R fits into big-league production environments. A frequent complaint against R is that although R is fine prototyping tool it is not able to handle production environments. Well, that’s just not true. In fact, it is straightforward to build a model in R, translate...

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R Still On Top

March 24, 2011
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R Still On Top

According to the Google Ngram corpus, R is still the top rated statistical software package. Ok, I’m just kidding. That plot is worthless. All the data are from books published between the years 1890 and 2008, and none of those software packages wou...

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Silver Is A Weighted Coin

March 24, 2011
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Silver Is A Weighted Coin

editorial note: there is an error in the code explained below the code. When you flip a quarter, you normally assume the coin is fair and that there is a 50% chance of getting either heads or tails. Option pricing assumes the world of trading is f...

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Generate MP3 waveforms with Ruby and R

March 24, 2011
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Generate MP3 waveforms with Ruby and R

I blame Rully for this. If it wasn’t for him I wouldn’t have been obsessed with this and spent a good few hours at night figuring it out last week. It all started when Rully mentioned that he knew how many beeps there are in the Singapore MRT (subway system) ‘doors closing’ warning. There are

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Day #11 R graphs as nodes

March 24, 2011
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Today my company supervisor isn’t at work so he gave me (and the other students) a task-list. I have to check the availability of the following R scripts. Whether or not they work how they should in Knime. While doing these tasks, at the main tim...

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