Monthly Archives: February 2012

Generation of correlated random numbers: recommended article

February 29, 2012
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Generation of correlated random numbers: recommended article

This quick blog entry to share an excellent article of Thijs van den Berg entitled Generating Correlated Random Numbers. This author describes in a nicely way how to generate sequences of correlated random numbers using the Cholesky decomposition, and a Eigenvector … Continue reading

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R turns 12; R 2.14.2 is out

February 29, 2012
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As promised by the R Core Group, R 2.14.2 is out. This is the final patchlevel of the R 2.14.x series (R 2.15.0 is due on March 30), and so R 2.14.2 will be the R engine for the next release of Revolution R Enterprise in a couple of months. Today also marks the 12th anniversary since R 1.0.0...

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Massive Increase in Ethanol Production

February 29, 2012
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Massive Increase in Ethanol Production

Description: Yearly production of Ethanol in the United States since 1980. Data: http://www.ethanolrfa.org/ Analysis: When it comes to fuel - especially for transportation - oil is king. In 2010, the United States imported 180.8 billion gallons ...

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A Direct Marketing In-flight Forecasting System

February 29, 2012
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A Direct Marketing In-flight Forecasting System

This is an edited version of A Direct Marketing In-flight Forecasting System. The original article was written by Shannon Terry and Ben Ogorekm, Nationwide Insurrance, in order to enter the “Applications of R in Business” contest organised by Revolution Analytics. This is the winning entry of the contest. I added some notes in the third

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Programatically rename files (or do other stuff to them) in R

February 29, 2012
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In order to do something to a bunch of files at once, we first need a vector which contains the file paths of just the files we are interested in. startingDir<-"/myDirectory"filez<-list.files(startingDir,pattern="searchPattern")head(filez) "/m...

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Functional ANOVA using INLA – update

February 29, 2012
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Functional ANOVA using INLA – update

INLA author Håvard Rue wrote me to point out a problem in the Functional ANOVA code given in this post. I made a mistake in setting the precision of the fixed effects (I used “default” instead of “prec”). I’ve put Håvard’s corrected version of the code below.  

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Graphical message boxes with R package tcltk

February 29, 2012
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Graphical message boxes with R package tcltk

Sometimes you just need a graphical messagebox....know what I mean? If only because it pops up in front of all the other open windows and alerts you to the fact that your R script is waiting for you to do something, or is finished doing something el...

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ABC in Roma [R lab #1]

February 29, 2012
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ABC in Roma [R lab #1]

Here are the R codes of the R labs organised by Serena Arima in supplement of my lectures. This is quite impressive and helpful to the students, as illustrated by the first example below (using the abc software). I am having a great time teaching this “ABC in Roma” course, in particular because of the

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Statistics project ideas for students

February 29, 2012
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Here are a few ideas that might make for interesting student projects at all levels (from high-school to graduate school). I’d welcome ideas/suggestions/additions to the list as well. All of these ideas depend on free or scraped data, which means tha...

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XYZ geographic data interpolation, part 2

February 29, 2012
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XYZ geographic data interpolation, part 2



Having recently received a comment on a post regarding geographic xyz data interpolation, I decided to return to my original "xyz.map" function and open it up for easier interpretation. This should make the method easier to adapt and follow.

The above graph shows the distance to Mecca as interpolated from 1000 randomly generated lat/lon...

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