Monthly Archives: April 2010

Lookup Performance in R

April 2, 2010
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Rumor has it that Joe Adler, author of the O’Reilly Book R in a Nutshell, has joined Linked In as a data scientist.  But that does not keep him from still pumping out some interesting content over at OReilly.com. His latest article is about lookup performance in R. He does a great job giving code

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Opening Statements on Markov Chain Monte Carlo

April 1, 2010
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Opening Statements on Markov Chain Monte Carlo

This quarter I am TAing UCLA’s Statistics 102C. Introduction to Monte Carlo Methods for Professor Qing Zhou. This course did not exist when I was an undergraduate, and I think it is pretty rare to teach Monte Carlo (minus the bootstrap if you count that) or MCMC to undergrads. I am excited about this class because to me, MCMC...

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Frank Harrell’s Regression Modeling Strategies Course Handouts

April 1, 2010
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The previously mentioned Regression Modeling Strategies short course taught by Frank Harrell is nearly over. Here are the handouts (PDF) from the course. Keep an eye out here, I'll be writing a few more posts in the near future on topics Frank covered...

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Quantile LOESS – Combining a moving quantile window with LOESS (R function)

April 1, 2010
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Quantile LOESS – Combining a moving quantile window with LOESS (R function)

In this post I will provide R code that implement’s the combination of repeated running quantile with the LOESS smoother to create a type of “quantile LOESS” (e.g: “Local Quantile Regression”). This method is useful when the need arise to fit robust and resistant (Need to be verified) a smoothed line for a quantile (an example for such a...

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Because it’s Thursday: Epidemiology of the Undead

April 1, 2010
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Because it’s Thursday: Epidemiology of the Undead

Noted statistician Andrew Gelman has teamed up with occultist George Romero to address the most serious public-health threat of out time: Zombies. They've published a paper in the journal Biomastika, "How many zombies do you know?" to propose the use of indirect survey methods to measure outbreaks of the undead: Abstract: The zombie menace has so far been studied...

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Plots in R and the ImageJ visualization

April 1, 2010
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Plots in R and the ImageJ visualization

If you plot data in R and you would like to display the same data in the ImageJ view it is necessary to transfer the data matrix to ImageJ. The first thing which can be noticed is that the image data is displayed rotated because of the Bio7 approach to transfer data forth and back

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