Monthly Archives: April 2010

Repeated measures ANOVA with R (tutorials)

April 13, 2010
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Repeated measures ANOVA is a common task for the data analyst. There are (at least) two ways of performing “repeated measures ANOVA” using R but none is really trivial, and each way has it’s own complication/pitfalls (explanation/solution to which I was usually able to find through searching in the R-help mailing list). So for future reference, I am starting this page...

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Cherry Picking to Generalize ~ NASA Global Temperature Trends ~ enhanced w/ ggplot2

April 12, 2010
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Cherry Picking to Generalize ~ NASA Global Temperature Trends ~ enhanced w/ ggplot2

In a prior article, I tried to visualize the linear global temperatures trends for a grid of start and end years. The visual I created was confusing in that the specification of color scale was interdependent with the data values. I wanted a blue -> white -> red scale of the temperatures indicating cool ->

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Using MKL-Linked R in Eclipse

April 12, 2010
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Using MKL-Linked R in Eclipse

Setting up Eclipse to use MKL-Linked RIn my previous post, I showed how to compile R 2.10.1 using Intel's Math Kernel Library for the BLAS/LAPACK interface. Even though it takes a bit of time to setup, I think the noticeably improved calculation speed justifies the effort. Although I'm happy to use R from the command line for basic stuff,...

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Using MKL-Linked R in Eclipse

April 12, 2010
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Using MKL-Linked R in Eclipse

Setting up Eclipse to use MKL-Linked RIn my previous post, I showed how to compile R 2.10.1 using Intel's Math Kernel Library for the BLAS/LAPACK interface. Even though it takes a bit of time to setup, I think the noticeably improved calculation speed justifies the effort. Although I'm happy to use R from the command line for basic stuff,...

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Jeroen Ooms’s ggplot2 web interface – a new version released (V0.2)

April 12, 2010
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Good news. Jeroen Ooms released a new version of his (amazing) online ggplot2 web interface: yeroon.net/ggplot2 is a web interface for Hadley Wickham’s R package ggplot2. It is used as a tool for rapid prototyping, exploratory graphical analysis and education of statistics and R. The interface is written completely in javascript, therefore there is no need to install anything on the...

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pgfSweave version 1.0.5 released

April 12, 2010
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Version 1.0.5 is now on CRAN. This version brings some bug fixes as well as two new features: Unlabeled code chunks are now allowed. The correct version of PGF is now checked for on startup. If the version is < 2.00, the package will fail to load....

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Arizona court rules statistical sampling is legal

April 12, 2010
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A court in Arizona has ruled that statistical sampling is legal for determining damages awarded to individual claimants when there are thousands of similar cases to be assessed simultaneously. In a case where 30,000 claims were filed Maricopa County, AZ by hospitals for improper reimbursement, the trial judge appointed a former judge as a special master in the case...

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Working with themes in Lattice Graphics

April 12, 2010
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Working with themes in Lattice Graphics

The Trellis graphics approach provides facilities for creating effective graphs with a consistent look and feel and one of the good things about the system is the use of themes to define the colour, size and other features of the components that make up a graph. The lattice package in R is an implementation of

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Example 7.32: Add reference lines to a plot; fine control of tick marks

April 12, 2010
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Example 7.32: Add reference lines to a plot; fine control of tick marks

Sometimes it's useful to plot regular reference lines along with the data. For a time-series plot, this can show when critical values are reached in a clearer way than simple tick marks.As an example, we revisit the empirical CDF plot shown in Example...

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Anecdotal Evidence that Facebook Stores all Clicks?

April 11, 2010
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Anecdotal Evidence that Facebook Stores all Clicks?

This is not really news. A few months ago, news broke that Facebook recorded each user’s clicks and profile views in a database. Of course, I am not at all surprised. I would be more surprised if they didn’t store every single click. By now, most people have some sense as to how Facebook’s recommendation system works. It typically performs...

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