Prime Parallels for Load Balancing

July 5, 2010
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Prime Parallels for Load Balancing

Having finally popped the stack on computing prime numbers with R in Part II and Part III, we are now in a position to discuss their relevance for computational scalability.My original intent was to show how poor partitioning of a workload can defeat the linear scalability expected when full parallelism is otherwise attainable, i.e., zero...

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Hacker News Religion Poll

July 5, 2010
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Hacker News Religion Poll

Hacker News user post polls from time to time - the following code constructs a bar chart based upon the responses to a recent poll on the stated religious affiliation of Hacker news users (parsed straight from the site).  The chart above is as of...

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Make R speak SQL with sqldf

July 5, 2010
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Make R speak SQL with sqldf

The R community is unique as programming communities go.  Many users of R come from academia and have a relatively extensive mathematical background.  The R community has developed in relative isolation from some other areas of programming th...

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Convergence diagnostics with MCMCglmm

July 5, 2010
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Convergence diagnostics with MCMCglmm

MCMCglmm does not produce more than one chain. So the way to check convergence is to run the model twice, each with different starting values, then conduct the diagnostic with:gelman.diag(m1$Sol, m2$Sol)

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Excellent R Code Format Package

Excellent R Code Format Package

I have been looking for this type of package for several days, and luckily found it today. Unquestionable R is powerful, however, R programming is unfriendly as far as I concern, mainly due to the lack of format shortcut, which makes the R codes rathe...

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Happy 4th of July

July 3, 2010
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Happy 4th of July

library(maps)states <- data.frame(map("state", plot=FALSE))plot(states, type = "l", col = "navy", axes = FALSE, xlab = "", ylab = "")title("Happy 4th of July",  col.main = "red")

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Europe Data set:> eurodist                 Athens Barcelona…

July 3, 2010
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Europe
Data set:> eurodist                 Athens Barcelona…

Europe Data set:> eurodist                 Athens Barcelona Brussels Calais Cherbourg Cologne CopenhagenBarcelona         3313                                                   

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Get up and running with R, Sweave, and LaTex

July 2, 2010
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Get up and running with R, Sweave, and LaTex

There are a lot of great references on the web on how to levarage LaTeX for reporting and presentations (beamer), but as someone who is completely new to R and reproducible research, I was having a pretty hard time figuring out simply what to do (what tools, where do you edit, etc.). Eclipse as a

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Visualization of regression coefficients (in R)

July 2, 2010
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Visualization of regression coefficients (in R)

Update (07.07.10): The function in this post has a more mature version in the “arm” package. See at the end of this post for more details. * * * * Imagine you want to give a presentation or report of your latest findings running some sort of regression analysis. How would you do it? This was exactly the question...

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The case of the missing zeroes

July 2, 2010
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The case of the missing zeroes

Political polling is a big industry these days, especially here in the US, and both mainstream news outlets and many of the bigger political blogs commission their own polls to measure (for example) the popularity of a sitting or candidate politician or policy. In the last week though, a very public spat has erupted between the left-leaning political blog...

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Creating a Presentation with LaTeX Beamer – Getting Started

July 2, 2010
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Creating a Presentation with LaTeX Beamer – Getting Started

The LaTeX beamer package can be used to create appealing presentations for many applications. A working knowledge of LaTeX is required but once the initial learning curve and transition is made from a visual word processor to a markup based approach the benefits are worth the initial investment of time. Title Pages In a previous post we

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An experiment in A/B Testing my Résumé

July 1, 2010
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An experiment in A/B Testing my Résumé

Objective I’ll admit it: my résumé doesn’t stand out. I’ve had some great internships, but also a tendency to work for companies that aren’t (yet!) household names. And though I’m doing fine academically, it’s not well enough to stand out … Continue reading →

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Maps without map packages

July 1, 2010
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Maps without map packages

LATITUDE + LONGITUDE + OVERPLOTTING FIX = MAPS Decision Science News is always learning stuff from colleague, physicist, mathlete, and all-around computer whiz Jake Hofman. Today, it was a quick and clean way to make nice maps in R without using any map packages: just plot the latitude and longitude of your data points (e.g.

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UseR! 2010 registration extended until July 4

July 1, 2010
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Registration for the worldwide R user conference, useR! 2010, closed on June 20. But it seems like a few folks weren't aware of the early deadline, and missed out on registering. Never fear! Due to overwhelming demand, registration has re-opened until midnight on July 4. You'll need to hurry -- there are only 30 spots left -- so get...

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Call for Papers: Special Issue in JSS for "Magnetic Resonance Imaging in R"

July 1, 2010
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Call for Papers: Special Issue in JSS for "Magnetic Resonance Imaging in R"

We hereby call for the submission of original papers for a Special Issue of the Journal of Statistical Software (JSS - http://www.jstatsoft.org)Magnetic Resonance Imaging in R planned for Summer 2011. The deadline for submission is October 31, 2...

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Call for Papers: Special Issue in JSS for "Magnetic Resonance Imaging in R"

July 1, 2010
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Call for Papers: Special Issue in JSS for "Magnetic Resonance Imaging in R"

We hereby call for the submission of original papers for a Special Issue of the Journal of Statistical Software (JSS - http://www.jstatsoft.org)Magnetic Resonance Imaging in R planned for Summer 2011. The deadline for submission is October 31, 2...

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Can you spot the Error?

July 1, 2010
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Can you spot the Error?

Peter Huber referred to “the rawness of raw data”, a kind of data we would not expect to find in a textbook. The book of Fahrmeir and Tutz on multivariate modelling refers to the visual impairment data from Liang et al., 1992 in table 3.12: Nothing wrong here at first sight; but how would you

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Simple Dummy R GUI Generator

Simple Dummy R GUI Generator

Imagine you finish a dirty coding project and want to present to your boss who is not in a good mood (may not be occasionally), how are you going to start? Show him your hundreads of lines code, point to the lines, explain what the arguments and outputs are? No, it is not a smart way since you are...

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CRAN Search

June 30, 2010
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CRAN Search

Here's a ditty to search the cran R packages by descriptioncranSearch = function(q=''){  library(XML)  u<-'http://cran.r-project.org/web/packages/'  d<-readHTMLTable(u)  d]$V1  lib.names <-...

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My Experience at Hadoop Summit 2010 #hadoopsummit

June 30, 2010
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My Experience at Hadoop Summit 2010 #hadoopsummit

This week I had the opportunity the trek up north to Silicon Valley to attend Yahoo’s Hadoop Summit 2010. I love Silicon Valley. The few times I’ve been there the weather was perfect (often warmer than LA), little to no traffic, no road rage and people overall seem friendly and happy. Not to mention there are so many trees...

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Drawing pedigree examples using the kinship R package

June 30, 2010
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Drawing pedigree examples using the kinship R package

I have previously provided sort of an overview about plotting the pedigrees, then specifically using the Graphiviz, while I have lately used the TikZ LaTeX (see slides 11-15) system (see more example). The later gives great (beautiful) results, but at the cost of writing TikZ code - it is not that horible, just time consuming...

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Drawing pedigree examples using the kinship R package

June 30, 2010
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Drawing pedigree examples using the kinship R package

I have previously provided sort of an overview about plotting the pedigrees, then specifically using the Graphiviz, while I have lately used the TikZ LaTeX (see slides 11-15) system (see more example). The later gives great (beautiful) results, but at the cost of writing TikZ code - it is not that horible, just time consuming...

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Contest: Road Traffic Prediction for Intelligent GPS Navigation

June 30, 2010
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Contest: Road Traffic Prediction for Intelligent GPS Navigation

About prize baring contests Competition with prizes are an amazing thing. If you are not sure of that, I urge you to listened to Peter Diamandis talk about his experience with the X prize (start listening at minute 11:40): At short – prizes can give up to 1 to 50 ratio of return on investment of the people giving...

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June 2010 edition of R Journal available

June 30, 2010
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The latest edition of the R Journal is now available. This issue includes in-depth articles on the packages IsoGene, glmmBUGS, cshapes, tmvtnorm, neuralnet, glmperm and exactci/exact2x2, plus an example of reproducible research in R. There's also a review of the book A Beginner's Guide to R. The complete edition is available for download in PDF format at the link...

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Rmetrics slides

June 30, 2010
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I presented Rcpp at the Rmetrics conference earlier today, this was a really good opportunity to look back at all the work Dirk and I have been commiting into Rcpp. I've uploaded my slides here (pdf) and on slideshare : Rcpp: Seemless R and C++V...

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R Journal 2/1

June 30, 2010
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R Journal 2/1

R Journal 2/1 is out! Grab it from here.

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R Journal 2/1

June 30, 2010
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R Journal 2/1

R Journal 2/1 is out! Grab it from here.

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Setting graph margins in R using the par() function and lots of cow milk

June 30, 2010
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Setting graph margins in R using the par() function and lots of cow milk

It is fairly straightforward to set the margins of a graph in R by calling the par() function with the mar (for margin!) argument. For example, par(mar=c(5.1,4.1,4.1,2.1) sets the bottom, left, top and right margins respectively of the plot region in number of lines of text. Another way is by specifying the margins in inches

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Rcpp 0.8.3

June 29, 2010
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A new version 0.8.3 of Rcpp is now CRAN and in Debian. It comes about three weeks after the 0.8.2 release. And even though we promised to concentrate on documentation, it contains a raft of new features: The addition of what we dub Rcpp sugar: some ...

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