# Monthly Archives: December 2011

## Comparing model selection methods

December 2, 2011
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The standard textbook analysis of different model selection methods, like cross-validation or validation sample, focus on their ability to estimate in-sample, conditional or expected test error. However, the other interesting question is to compare the...

## O’Reilly’s Data Science Kit – Books

December 2, 2011
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It is not as if I don't have enough books (and material on the web) to read. But this list compiled by the O'Reilly team should make any data analyst salivate.http://shop.oreilly.com/category/deals/data-science-kit.doThe Books and Video included in the...

## Easy cell statistics for factorial designs

December 2, 2011
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A common task when analyzing multi-group designs is obtaining descriptive statistics for various cells and cell combinations. There are many functions that can help you accomplish this, including aggregate() and by() in the base installation, summaryBy() in the doBy package, and … Continue reading →

December 2, 2011
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## Wasting away again in Martingaleville

December 1, 2011
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Alright, I better start with an apology for the title of this post. I know, it’s really bad. But let’s get on to the good stuff, or, perhaps more accurately, the really frightening stuff. The plot shown at the top of this post is a simulation of the martingale betting strategy. You’ll find code for

## Backtesting with Short positions

December 1, 2011
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I want to illustrate Backtesting with Short positions using an interesting strategy introduced by Woodshedder in the Simple, Long-Term Indicator Near to Giving Short Signal post. This strategy was also analyzed in details by MarketSci in Woodshedder’s Long-Term Indicator post. The strategy uses the 5 day rate of change (ROC5) and the 252 day rate

## Interviews on Revolution R Enterprise 5.0

December 1, 2011
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For those looking for more background behind the updates in Revolution R Enterprise 5.0, there are now a couple of interviews online where I talk about the new release. At IT Business Edge ("Revolution Analytics' Goal: Make R Analysis Enterprise-Friendly"), I had a chat with Loraine Lawson about how Revolution R Enterprise fits within the analytics stack, its big-data...

## A Friday round-up

December 1, 2011
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Just a brief selection of items that caught my eye this week. Note that this is a Friday as opposed to Friday, lest you mistake this for a new, regular feature. 1. R/statistics ggbio A new Bioconductor package which builds on the excellent ggplot graphics library, for the visualization of biological data. R development master