2772 search results for "gis"

DESeq vs edgeR Comparison

September 18, 2012
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DESeq vs edgeR Comparison

Update (Dec 18, 2012): Please see this related post I wrote about differential isoform expression analysis with Cuffdiff 2.DESeq and edgeR are two methods and R packages for analyzing quantitative readouts (in the form of counts) from high-throughput e...

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Embedding \(\LaTeX\) in Tumblr

September 18, 2012
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The classic Pythagorean identity is:  \(sin^2(\theta) + cos^2(\theta) =1 \) The binomial formula which calculates the probability of obtaining k tails when flipping a coin n times, with a assumed probability p for each trial is: \( P(E)   = {n \choos...

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Simple Parallel randomForest with doMC package

I have been exploring how to speed up some of my R scripts and have started reading about some amazing corners of R. My first weapon was the Rcpp and RcppArmadillo package. These are wonderful tools and even for someone that has never written c++ before, there are enough to examples and documentation to get started. I...

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Etymology

September 16, 2012
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Chris and I started this blog as an outlet for the work we were already doing every day: writing code and trying to avoid forgetting how we wrote it. To that end, gist.github.com is an extremely useful resource, and this blog allows us to add a little ...

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Mapping Bike Accidents in R

September 14, 2012
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Mapping Bike Accidents in R

At last weekend’s Hack Ta Ville event here in Montreal, I joined up with some talented urban planners and web devs to realize Vélobstacles. The idea of the project is to crowd source information on cycling conditions around the city. As with any crowd sourcing project, we were faced with the problem of seeding the

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OO in R

September 13, 2012
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OO in R

"Is there a package for obfuscating code in #rstats?", someone asked. "The S4 object system?!" came the snarky reply. If you're smiling right now, you know that it wouldn't be funny if it weren't at least a little bit true. Options: S3, S4 or R5? There can be little doubt that object oriented...

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A function to find the “Penultimax”

September 13, 2012
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A function to find the “Penultimax”

Penulti-what?  Let me explain: Today I had to iteratively go through each row of a donor history dataset and compare a donor’s maximum yearly donation total to the second highest yearly donation total.  In even more concrete terms, for each … Continue reading →

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Word Clouds in R

September 13, 2012
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Word Clouds in R

Thanks to the wordcloud package, it's super easy to make a word cloud or tag cloud in R.In this case, the words have been counted already. If you are starting with plain text, you can use the text mining package tm to obtain the counts. Other blog...

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Second Milano R net meeting

September 11, 2012
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Second Milano R net meeting

September 27, 2012 - 18:00 - 21:00 Fiori Oscuri Bistrot & Bar (www.fiorioscuri.it) Via Fiori Oscuri, 3 - Milano (Zona Brera) Continue reading →

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Item Response Theory: Developing Your Intuition

September 10, 2012
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Item Response Theory: Developing Your Intuition

Suppose that you accepted my argument from the last two posts on halo effects and bifactor models.  As you might recall, I argued that when respondents complete rating scales, they predominating rely on their generalized impression with a more minor role played by the specific features that the ratings were written to measure.  Consequently, we...

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