# Monthly Archives: October 2010

## Parametric Bootstrap Power Analysis of GISS Temp Data

October 24, 2010
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Previosly, I calculated a bunch of ad-hoc power curves from GISTEMP data. Power is essentially a reframing of the p-value, to see the significance of the trend lines in the global temps. However, power calculations are inherently very noisy, hence, my ad-hoc way of aggregating the data. Another method is to bootstrap through the responses

## Accessing R from Python using RPy2

October 24, 2010
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This past Tuesday I had the opportunity to present a short talk (a bit long) related to text mining at the Los Angeles R Users’ Group. Since I do most of my text mining in Python, I took this opportunity to discuss RPy2, an interface to R from Python. My slides are below: Accessing R from Python...

## Programming with R – Checking Function Arguments

October 24, 2010
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In a previous post we considered writing a simple function to calculate the volume of a cylinder by specifying the height and radius of the cylinder. The function did not have any checking of the validity of the function arguments which we will consider in this post. R has various functions that we can use to

## Generate your own Risk Characterization Theatre

October 24, 2010
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In the recent posts Visualizing Smoking Risk and Shades of grey I wrote about the use of “Risk Characterization Theatres” (RCTs) to communicate probabilities. I found the idea in the book The Illusion of Certainty, by Eric Rifkin and Edward Bouwer. Here is how they explain the RCTs: Most of us are familiar with the crowd in a

## Grabbing Tables in Webpages Using the XML Package

October 24, 2010
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ables are pretty common in web pages as data sources, and the most direct way to get these data is probably to copy and paste. This is OK if there are only two or three tables, and when we need to grab 5000 tables in 1000 web pages, we may not really wish to fulfill

## how to speak ggplot2 like a native, and Predictive Analytics World

October 24, 2010
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I was recently given the opportunity to re-present my ggplot2 talk, which I originally gave to the NYC R Meetup, to the DC R Meetup group. The Meetup was held co-located with the Predictive Analytics World conference in Alexandria, VA. (More on my thoughts on PAW below…) Contentwise, I made only small changes, changing a

## Le Monde puzzle [42]

October 24, 2010
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An interesting suduko-like puzzle for this week puzzle in Le Monde thi A 10×10 grid is filled by a random permutation of {0,…,99}. The 4 largest figures in each row are coloured in yellow and the 4 largest values in each column are coloured in red. What is the range of the number of yellow-and-red

## Reader suggestions on alternative ways to create combination dotplot/boxplot

October 24, 2010
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Kudos to several of our readers, who suggested simpler ways to craft the graphical display (combination dotplot/boxplot) from our most recent example.Yihui Xie combines a boxplot with a coarsened version of the PCS scores (using the round() function) u...

## R GUI now offers interactive graphics – Deducer 0.4-2 connects with iplots

October 24, 2010
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Earlier today, Ian Fwllows has announced the release of Deducer 0.4-2 and DeducerExtras 1.2 to CRAN (I copy his announcement here): Deducer 0.4-2 contains a few bug fixes, and an interface to the iplots package. With the new iplots interface it is now possible to do interactive plots with Deducer. An introductory example screen cast

## Aquamacs customizations (auctex, ESS)

October 23, 2010
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I gave an informal talk on my Mac based “workflow” at Stanford on Friday.  I talked a lot about Aquamacs as a tool for editing LaTeX (I use MacTeX) and for working with R (thanks auctex and ess, respectively).  Skim also got a mention; I emphasized TeX-PDF synchronization. Some of the students were asking for