Publications by Corey Chivers
R Workshop: Reproducible Research using Sweave for Beginers
Monday, April 30, 2012 14h-16h. Stewart Biology Rm w6/12 (Montreal) guRu: Denis Haine (Université de Montréal) Topics Reproducible research was first coined by Pr. Jon Claerbout, professor of geophysics at Stanford University, to describe that the results from researches can be replicated by other scientists by making available data, procedur...
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Heartbeat of a Cycling City: Bixi data at Hack/Reduce
The recent Hack/Reduce hackathon in Montreal was a tonne of fun. Our team tackled a data set of consisting of Bixi (Montreal’s bicycle share system) station states at one minute temporal resolution. We used Hadoop and mapreduce to pull out some features of user behaviours. One of the things we extracted was the flux at each station, which we de...
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More Bixi Data Visualization
I mentioned in a previous post that our team at the recent Hack/Reduce hackathon had some fun with a data set which consisted of Bixi station states at minute level temporal resolution. In addition to pulling out and plotting the flux at each station on an hourly basis, we also plotted the system state (number of bikes at each station) at each ti...
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Distribution of Oft-Used Bash Commands
Browsing commandlinefu.com today, I came across this little one-liner to display which commands I use most often. $ history | awk '{a[$2]++}END{for(i in a){print a[i] " " i}}' \ | sort -rn | head Here’s what I got: 283 ls 236 cd 52 cat 40 vim 36 sudo 27 ssh 27 rm 23 git 21 screen 21 R Yep, seems legit. I navigate and look at files a whole bun...
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Simulating Euro 2012
Why settle for just one realisation of this year’s UEFA Euro when you can let the tournament play out 10,000 times in silico? Since I already had some code lying around from my submission to the Kaggle hosted 2010 Take on the Quants challenge, I figured I’d recycle it for the Euro this year. The model takes a simulation based approach, using...
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R Workshop: Introducing Slidify – HTML5 slides from R markdown
Thursday, June 28th, 2012 19h. Tomson House: 650 McTavish, H3A 1Y2, Montréal, QC guRu: Ramnath Vaidyanathan (McGill University) Ramnath Vaidyanathan will introduce the group to slidify, his brand new R package. From the slidify website: “The objective of slidify is to make it easy to create reproducible HTML5 presentations from .Rmd files....
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Dynamical systems: Mapping chaos with R
Chaos. Hectic, seemingly unpredictable, complex dynamics. In a word: fun. I usually stick to the warm and fuzzy world of stochasticity and probability distributions, but this post will be (almost) entirely devoid of randomness. While chaotic dynamics are entirely deterministic, their sensitivity to initial conditions can trick the observer into s...
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Olympic body match and 1:1 BMI
In my morning attempt to read the whole internet before beginning work, I came across a program on the BBC website which allows you to see which Olympic athletes are your body doubles. Or rather, which athletes share your height and weight, and therefore your body mass index. Being a Canadian, I exist in an uneasy hybrid world of measurements, co...
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Simulation: The modeller’s laboratory
In his 2004 paper in Trends in Ecology and Evolution, Steven Peck argues: Simulation models can be used to mimic complex systems, but unlike nature, can be manipulated in ways that would be impossible, too costly or unethical to do in natural systems. Simulation can add to theory development and testing, can offer hypotheses about the way the wo...
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The essence of a handwritten digit
If you haven’t yet discovered the competitive machine learning site kaggle.com, please do so now. I’ll wait. Great – so, you checked it out, fell in love and have made it back. I recently downloaded the data for the getting started competition. It consists of 42000 labelled images (28×28) of hand written digits 0-9. The competition is a st...
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