Chinese versus Japanese editions

March 8, 2010
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Chinese versus Japanese editions

Last week, I got news from Springer Verlag about possibly two new editions of my books, one in Chinese and one in Japanese. These were bad news and good news: the bad news was that the Chinese edition was actually a reprint of our original book,  Monte Carlo Statistical Method, by a Chinese publishing company.

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White House taps Edward Tufte to explain the stimulus

March 8, 2010
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White House taps Edward Tufte to explain the stimulus

Edward Tufte, a pioneer of effective data visualization (and a personal hero) has just been appointed by the White House to the Recovery Independent Advisory Panel. This panel advises The Recovery Accountability and Transparency Board, whose job is to track and explain $787 billion in recovery stimulus funds. Tufte explains: I'm doing this because I like accountability and transparency,...

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Weird dietary habits in the US

March 8, 2010
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Weird dietary habits in the US

Using this database of food consumption data the blog Canibais e Reis kindly put together, I calculated all values for which the US was at least 2 standard deviations from the world average. Here are the outliers in standard deviations from the w...

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Weird dietary habits in the US

March 8, 2010
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Weird dietary habits in the US

Using this database of food consumption data the blog Canibais e Reis kindly put together, I calculated all values for which the US was at least 2 standard deviations from the world average. Here are the outliers in standard deviations from the w...

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Chilean earthquake: impact of the tsunami

March 8, 2010
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Chilean earthquake: impact of the tsunami

The National Oceanic and Atmospheric Administration (NOAA) has a page with some interesting information about last week's earthquake in Chile, but what really stood out for me was this chart of the predicted wave heights around the globe resulting from the associated tsunami: Click to enlarge: it's a fascinating chart. Although labelled a forecast, from the explanations on the...

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Example 7.26: probability question

March 8, 2010
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Example 7.26: probability question

Here's a surprising problem, from the xkcd blog.Suppose I choose two (different) real numbers, by any process I choose. Then I select one at random (p= .5) to show Nick. Nick must guess whether the other is smaller or larger. Being right 50% of the ...

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R: Eliminating observed values with zero variance

March 8, 2010
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R: Eliminating observed values with zero variance

I needed a fast way of eliminating observed values with zero variance from large data sets using the R statistical computing and analysis platform. In other words, I want to find the columns in a data frame that has zero variance. And as fast as possible, because my data sets are large, many, and changing fast....

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R: Eliminating observed values with zero variance

March 8, 2010
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R: Eliminating observed values with zero variance

I needed a fast way of eliminating observed values with zero variance from large data sets using the R statistical computing and analysis platform. In other words, I want to find the columns in a data frame that has zero variance. And as fast as possible, because my data sets are large, many, and changing fast....

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InfoChimps

March 7, 2010
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InfoChimps

This looks interesting: http://infochimps.org/search?query=soil

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ggplot and concepts — what’s right, and what’s wrong

March 7, 2010
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ggplot and concepts — what’s right, and what’s wrong

A few months back I gave a presentation to the NYC R Meetup. (R is a statistical programming language. If this means nothing to you, feel free to stop reading now.) The presentation was on ggplot2, a popular package for generating graphs of data and statistics. In the talk (which you can see here, including

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A nice link: “Some hints for the R beginner”

March 7, 2010
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Patrick Burns just posted to the mailing list the following massage: There is now a document called “Some hints for the R beginner” whose purpose is to get people up and running with R as quickly as possible. Direct access to it is: http://www.burns-stat.com/pages/Tutor/hints_R_begin.html JRR Tolkien wrote a story (sans hobbits) called ‘Leaf by Niggle’ that has always resonated with me. I...

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One R Tip A Day meets Tecnica Arcana

March 7, 2010
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One R Tip A Day meets Tecnica Arcana

For italian speaking people only (sorry!). Carlo il curatore dell'ottimo podcast tecnologico Tecnica Arcana mi ha intervistato sulla mia professione e su R. Qui potete scaricare l'intervista in formato mp3.

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Ecological Modelling with “R”

March 7, 2010
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Here i present some Books and Articles about Ecological Modelling and “R”. Since “R” is integrated in Bio7 all the presented methods in the Books and Articles can also be useful together with Bio7. Books: Ellner, Stephen P. & Guckenheimer, John (2006). Dynamic Models in Biology. Princeton University Press Bolker B (2008) Ecological Models and

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Intermarket Whac-A-Mole

March 6, 2010
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Intermarket Whac-A-Mole

Every trader that looks at more than one market throughout the day will recognize that there is a certain symmetrical relationship between certain markets at certain times. The confounding thing about these intermarket relationships is that they are fl...

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schoolmath

March 6, 2010
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schoolmath

In connection with the Le Monde puzzle of last week, I was looking for an R function that would give me the prime factor decomposition of any integer. Such a function exists within the package schoolmath, developped by Joerg Schlarmann and Josef Wienand. It is called prime.factor and it returns the prime factors of any

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Visualizing Drought

March 6, 2010
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Visualizing Drought

The impacts of drought depend on time-scale. On short time-scales, drought means dry soil. On long time-scales, it means dry rivers and empty reservoirs. A region may simultaneously experience dry conditions on one time-scale and wet conditions on another e.g. wet soil but low streamflow or visa versa. Standardized Precipitation Index (SPI) is a widely

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Contingency Tables – Fisher’s Exact Test

March 6, 2010
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A contingency table is used in statistics to provide a tabular summary of categorical data and the cells in the table are the number of occassions that a particular combination of variables occur together in a set of data. The relationship between variables in a contingency table are often investigated using Chi-squared tests. The simplest contingency

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Posterior likelihood

March 6, 2010
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Posterior likelihood

At the Edinburgh mixture estimation workshop, Murray Aitkin presented his proposal to compare models via the posterior distribution of the likelihood ratio. As already commented in a post last July, the positive aspect of looking at this quantity rather than at the Bayes factor is that the priors are then allowed to be improper if

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oro.nifti 0.1.3

March 5, 2010
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The R package oro.nifti has been released.  Medical imaging data, in NIfTI or Analyze formats, may be input, created from scratch, converted from DICOM (using oro.dicom) and output to a file. 

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oro.nifti 0.1.3

March 5, 2010
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The R package oro.nifti has been released.  Medical imaging data, in NIfTI or Analyze formats, may be input, created from scratch, converted from DICOM (using oro.dicom) and output to a file. 

Read more »

InformationWeek on Urlocker

March 5, 2010
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InformationWeek published today a profile of Zack Urlocker, the former MySQL executive who recently joined REvolution's board: Former MySQL staffer Zack Urlocker is going to try to do for predictive analytics what he once did for relational database systems: bring open source code to a user population that hasn't necessarily had access to the technology before. REvolution Computing of...

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Because it’s Friday: Why a Salad Costs More than a Big Mac

March 5, 2010
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Because it’s Friday: Why a Salad Costs More than a Big Mac

In the US, at least. Via The Consumerist: Incidentally, the US FDA doesn't publish pyramids like this any more: it's now a garish personalized 2-d triangle with stripes. But at least it doesn't make the error of dimension committed by the left-hand pyramid: that orange section is a hell of a lot larger than 74% of the volume. The...

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GLMM revisted

March 5, 2010
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GLMM revisted

A short while ago, I reported some discrepancies between the results produced by "lme4" and other R packages as well as Stata. Today I upgraded to the most recent version of "lme4a" and re-ran my model. The error of false convergence disappea...

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R amusements

March 5, 2010
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R amusements

On a lark, and to kill a bit of time, I was running the R fortune command looking for references to SAS. Here’s what two successive random fortunes turned up. Can there be two more antipodal opinions about the same product? I laughed out loud. > fortune(‘SAS’) There are companies whose yearly license fees to

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Example 7.25: compare draws with distribution

March 5, 2010
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Example 7.25: compare draws with distribution

In example 7.24, we demonstrated a Metropolis-Hastings algorithm for generating observations from awkward distributions. In such settings it is desirable to assess the quality of draws by comparing them with the target distribution.Recall that the dis...

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Getting data from an image (introductory post)

March 5, 2010
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Getting data from an image (introductory post)

Hi there! This blog will be dedicated to data visualization in R. Why? Two reasons. First, when it comes to statistics, I am always starting by some exploratory analyses, mostly with plots. And when I handle large quantities of data, it’s nice to make some graphs to get a grasp about what is going on.

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Accessing Climate Change Data and a Custom Panel Function for Filled Polygons

March 4, 2010
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Accessing Climate Change Data and a Custom Panel Function for Filled Polygons

GCS Model Grids Recently finished some collaborative work with Vishal, related to visualizing climate change data for the SEI. This project was funded in part by the California Energy Commission, with additional technical support from the Google Earth Team. One of the final products was an...

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An email about mixtures

March 4, 2010
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An email about mixtures

As a coincidence, or not, I received the following email just before starting our mixture estimation workshop (the above is Ben Nevis on Monday, whose skyline really looks like a three component mixture!) and giving a discussion on label switching: I am implementing a Markov-Chain Monte Carlo method for Gibbs sampling from a simple mixture

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Yet Another plyr Example

March 4, 2010
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Yet Another plyr Example

another plyr example quantiles (0.05, 0.25, 0.5, 0.75, 0.95) of DSC by temperature bin There are plenty of good examples on how to use functions from the plyr package. Here is one more, demonstrating how to use ddply with a custom function. Note that there...

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