Monthly Archives: February 2012

recents advances in Monte Carlo Methods

February 8, 2012
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recents advances in Monte Carlo Methods

Next Thursday (Jan. 16), at the RSS, there will be a special half-day meeting (afternoon, starting at 13:30) on Recent Advances in Monte Carlo Methods organised by the General Application Section. The speakers are Richard Everitt, University of Oxford, Missing data, and what to do about it Anthony Lee, Warwick University, Auxiliary variables and many-core

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RStudio Server part 3: using an ssh tunnel for high performance

February 8, 2012
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In part 2 of this series of posts on RStudio Server, I commented that I suspected that RStudio Server would be fast. The first time I tried this from a remote connection, I was disappointed with the performance. Many companies… See more ›

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A spell-checker in R

February 7, 2012
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A spell-checker in R

I came across Dr. Peter Norvig’s blog about writing a basic spell-checker (http://norvig.com/spell-correct.html), and just had to try to implement it in R. Please excuse the ugly-ish code (I have not optimized it or commented it adequately at this point, but you can get the idea of what it does by reading Dr. Norvig’s blog).

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Two incredibly useful functions to throw into your .rprofile

February 7, 2012
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I’ve neglected this blog for quite some time but I’m getting around to finishing up a bunch of draft posts. But here is a quick one: Listing objects in your global environment A simple ls() doesn’t really tell you enough useful information at a glance. Most often I just want to know what I named

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What’s new in futile.matrix 1.1.2

February 7, 2012
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What’s new in futile.matrix 1.1.2

This is an exciting release of futile.matrix, which in some ways the package grows up and finds its purpose. It …Continue reading »

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updated slides for ABC PhD course

February 7, 2012
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updated slides for ABC PhD course

Over the weekend, I have added a few slides referring to recent papers mentioning the convergence of ABC algorithms, in particular the very relevant paper by Dean et al. I had already discussed in an earlier post. (This is taking a larger chunk of my time than expected! I am glad I will use the

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Example 9.20: visualizing Simpson’s paradox

February 7, 2012
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Example 9.20: visualizing Simpson’s paradox

Simpson's paradox is always amazing to explain to students. What's bad for one group, and bad for another group is good for everyone, if you just collapse over the grouping variable. Unlike many mathematical paradoxes, this arises in a number of real...

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"R": PLS Regression (Gasoline) – 004

February 7, 2012
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"R": PLS Regression (Gasoline) – 004

In the previous post we plot the Cross Validation predictions with:> plot(gas1, ncomp = 3, asp = 1, line = TRUE)We can plot the fitted values instead with:> plot(gas1, ncomp = 3, asp = 1, line = TRUE,which=train) Graphics are different:Of course, using "train" we get  overoptimisc statistics and we should look...

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Gauging Interest in a Montreal R User Group

February 7, 2012
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Gauging Interest in a Montreal R User Group

Some of us over at McGill’s Biology Graduate Student Association have been developing and delivering R/Statistics workshops over the last few years. Through invited graduate students and faculty, we have tackled  everything from multi-part introductory workshops to get your feet wet, to special topics such as GLMs, GAMs, Multi-model inference, Phylogenetic analysis, Bayesian modeling, Meta-analysis,

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What are the most popular bike routes in London?

February 7, 2012
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What are the most popular bike routes in London?

James Cheshire, R user and lecturer at the UCL Centre for Advanced Spatial Analysis, created this map of the most trafficked cycle routes in London: Click to enlarge, it's a gorgeous chart. The bicycle traffic data comes from London's public cycle-hire facility, which currently is only available in central London (which is why you don't see much activity in...

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