Publications by flodel
The 50 most used R packages
Ask anyone what makes R a great language, one argument that often comes back is its very active community. Proof is the impressive number of packages contributed by developers from all horizons and backgrounds. The CRAN website alone lists 3,725 packages but are they all reliable or even useful? Certainly not.The crantastic.org website is a grea...
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A gallery view for Craigslist
As much as I love Craigslist, I sometimes find the interface a bit limited. My biggest wish? That there was an option for showing the search results as an image gallery, like eBay has. This could prove quite useful for browsing things like antiques, furniture, art: categories where I only need a quick glance at an object’s picture and I imme...
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Optical Art with R
Last week, in a post entitled Bridget Riley exhibition in London, the author Markus Gesmann wrote an R script reproducing one of Riley’s famous art pieces: Movement in Squares.This reminded me of my own first “brush” with Op art. It was in art class years ago, our professor (Madame Vitré) had asked that we recreate an interesti...
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How I cracked Troyis (the online flash game)
Troyis™ is an addictive online flash game where you move a chess knight through increasingly difficult puzzles. After hours and hours of playing, sometimes late into the night, I decided I’d waste even more of my time and write a little program that can play the game on its own. The result is quite amazing — imagine Garry Kasparov riding ...
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Search and replace: Are you tired of nested `ifelse`?
It happens all the time: you have a vector of fruits and you want to replace all bananas with apples, all oranges with pineapples, and leave all the other fruits as-is, or maybe change them all to figs. The usual solution? A big old nested `ifelse`: Ok, that didn’t look too bad, especially with the code and fruits nicely aligned. But what if I...
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R and the last comma
In R, every comma matters. When creating a vector, c(1, 2, 5) will do the right thing, but add one unfortunate comma and c(1, 2, 5,) will greet you with a deadly Error in c(1, 2, 5, ) : argument 4 is empty. Other languages like Perl are less strict when defining basic data structures: having a comma after the last item is allowed. This can be par...
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