Monthly Archives: August 2010

Where to Start with PDQ?

August 30, 2010
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Where to Start with PDQ?

Once you've downloaded PDQ with a view to solving your performance-related questions, the next step is getting started using it. Why not have some fun with blocks? Fun-ctional blocks, that is. Since all digital computers and network systems can be considered as a collection of functional blocks and these blocks often contain buffers, their performance can be modeled...

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Taking R to the Limit: Large Datasets; Predictive modeling with PMML and ADAPA

August 30, 2010
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Taking R to the Limit: Large Datasets; Predictive modeling with PMML and ADAPA

During the first part of our meeting, Ryan Rosario presented on the topic of large datasets in R. Video, slides and code of the talk “Taking R to the Limit: Large Datasets” by Ryan Rosario at the Los Angeles area … Continue reading →

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Sweet bar chart o’ mine

August 30, 2010
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Sweet bar chart o’ mine

Last week I was asked to visualise some heart rate data from an experiment. ... The standard way of displaying a time series (that is, a numeric variable that changes over time) is with a line plot. ... The experimenters, however, wanted a bar chart. I hadn't considered this use of a barchart before, so it was interesting...

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Example 8.3: pyramid plots

August 30, 2010
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Example 8.3: pyramid plots

Pyramid plots are a common way to display the distribution of age groups in a human population. The percentages of people within a given age category are arranged in a barplot, often back to back. Such displays can be used distinguish males vs. femal...

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Wanted: R Analysis of New Scientist Covers

August 30, 2010
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Wanted: R Analysis of New Scientist Covers

Peter Aldhous and Jim Giles -- from New Scientist's San Francisco bureau -- are looking for a statistician and R user to take part in an interesting data analysis challenge, and also be part of a future article in the magazine. They were inspired by this rather tongue-in-cheek presentation where Sebastian Wernicke analyzed videos, transcripts and ratings of TED...

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US House Election Results Visualized Five Ways

August 30, 2010
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US House Election Results Visualized Five Ways

The Democratic major-party vote share of US House elections 2002-2008 visualized 5 different ways.

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Graphing Highly Skewed Data

August 30, 2010
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Graphing Highly Skewed Data

Graphing data with a few outliers is challenging, and some solutions are better than others. Here is a comparison of the alternatives.

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GEO database: curation lagging behind submission?

August 30, 2010
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GEO database: curation lagging behind submission?

I was reading an old post that describes GEOmetadb, a downloadable database containing metadata from the GEO database. We had a brief discussion in the comments about the growth in GSE records (user-submitted) versus GDS records (curated datasets) over time. Below, some quick and dirty R code to examine the issue, using the Bioconductor GEOmetadb

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MCMC Diagnostics in R with the coda Package

August 29, 2010
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MCMC Diagnostics in R with the coda Package

This is a follow up to my recent post introducing the use of JAGS in R through the rjags package. In the comments on that post, Bernd Weiss encouraged me to write a short addendum that describes diagnostic functions that you should use to assess the output from an MCMC sampler. I’ve only been using

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Beta translation done!

August 29, 2010
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Beta translation done!

Once my team of four translators had handed back to me all the chapters of the French version of Introducing Monte Carlo Methods with R to me, I had to go over the book to ensure some minimal consistency between the chapters. I started the editing in the plane to Vancouver but did not get

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