# Monthly Archives: August 2012

## Adventures at My First JSM (Joint Statistical Meetings) #JSM2012

August 6, 2012
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During the past few decades that I have been in graduate school (no, not literally) I have boycotted JSM on the notion that “I am not a statistician.” Ok, I am a renegade statistician, a statistician by training. JSM 2012 was held in San Diego, CA, one of the best places to spend a week during the summer. This...

## Getting started with Sweave & knitr

August 6, 2012
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Cool woven artwork on the campus of Kansas University. The image is CC by Patrick Emerson I recently started to work with Sweave (by Friedrich Leisch)...

## Crawford-Howell (1998) t-test for case-control comparisons

August 6, 2012
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Cognitive neuropsychologists (like me) often need to compare a single case to a small control group, but the standard two-sample t-test does not work for this because the case is only one observation. Several different approaches have been proposed and in a new paper just published in Cortex, Crawford and Garthwaite (2012) demonstrate that the Crawford-Howell (1998) t-test...

## It is good to be explicit

August 6, 2012
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Being careful not to repeat the year 1901 mistake, I set the TZ variable before I run R. I have the same set of data that I convert as follows: dates values date1 date2 and then plot plot( date1, values )plot( date2, values ) To my surprise I end up with the following two...

## Visualize a random forest that classifies digits

August 5, 2012
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My last post uses random forest proximity to visualize a set of diamond shapes (the random forest is trained to distinguish diamonds from non-diamonds).This time I looked at the digits data set that Kaggle is using as the basis of a competition for "ge...

## Early August flotsam

August 5, 2012
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Back teaching a couple of subjects and it’s the constant challenge to find enough common ground with students so one can push/pull them to the other side of new concepts. We are not talking about complex hierarchical models using mixed … Continue reading →

August 5, 2012
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## London Olympics 100m men’s sprint results

August 5, 2012
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The 100m mean's sprint finals of the 2012 London Olympics are over and Usain Bolt won the gold medal again with a winning time of 9.63s. Time to compare the result with my forecast of 9.68s, posted on 22 July. My simple log-linear model predicted ...

## Counting CRAN Package Depends, Imports and LinkingTo

August 5, 2012
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The recent update by Søren Højsgaard's to his gRbase package for graphical models made it the 75th package to depend on our Rcpp package for R and C++ integration. So in a lighthearted weekend moment, I tweeted about gRbase being number...

## The R-Podcast Episode 9: Adventures in Data Munging Part 1

August 5, 2012
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It’s great to be back with a new episode after an eventful break! This episode begins a series on my adventures in data munging, a.k.a data processing. I discuss three issues that demonstrate the flexibility and versatility R brings for recoding messy values, important inconsistent data files, and pinpointing problematic observations and variables. We also