2702 search results for "GIS"

Finding Numeric Values of Strings using strsplit()

December 19, 2012
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Finding Numeric Values of Strings using strsplit()

Given a random list of words, can you find which has the lowest or highest numerical value when we apply a basic number:letter cipher?  A while back I asked David how he would solve this problem:  http://projecteuler.net/problem=42 Today’s post shows how to take a vector of words, parse them into each of the individual letters comprising the word, and...

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R in Insurance Conference, London, 15 July 2013

December 19, 2012
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R in Insurance Conference, London, 15 July 2013

The first conference on R in Insurance will be held on Monday 15 July 2013 at Cass Business School in London, UK. The intended audience of the conference includes both academics and practitioners who are active or interested in the applications of R in insurance.This one-day conference will focus on applications in insurance...

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Making Friends with Multicollinearity

December 18, 2012
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Not every system of independent variables can be decomposed into separate components, each with its own unique contribution.  Sometimes our individual variables behave “as a unit” and thus become so entangled that we cannot say where the effect of one variable begins and the effect of another variable ends.  In such cases, it might be best to ignore the ...

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Making prettier network graphs with sna and igraph

December 18, 2012
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Making prettier network graphs with sna and igraph

We’ve had some requests for ideas about how to make prettier network graphs, so here is one example, using the sna package for plotting, and the igraph package to calculate PageRank. The help file for gplot is pretty self-explanatory, but Melissa Clarkson has produced the most thorough and impressive guide for any R...

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Differential Isoform Expression With RNA-Seq: Are We Really There Yet?

December 17, 2012
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Differential Isoform Expression With RNA-Seq: Are We Really There Yet?

In case you missed it, a new paper was published in Nature Biotechnology on a method for detecting isoform-level differential expression with RNA-seq Data:Trapnell, Cole, et al. "Differential analysis of gene regulation at transcript resolution with RN...

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Who are the pollinators? (with R plot)

December 17, 2012
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Who are the pollinators? (with R plot)

I’ve been dreaming on writing a manuscript about who are the pollinators for a while, but it looks I’m not going to have the time soon, so here is an early draft of what the main figure should look like: It’s surprisingly … Continue reading →

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The Inverse Herfindahl–Hirschman Index as an “Effective Number of” Parties

December 17, 2012
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The Inverse Herfindahl–Hirschman Index as an “Effective Number of” Parties

I learned of the passing of Albert Hirschman on December 11, and while better and more instructive tributes to his life can be read elsewhere, I wanted to focus on a little piece of Hirschman’s work that I use all the time: the (inverse) Herfindahl–Hirschman Index. The HHI is basically a measure of market concentration, but...

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Dark matter top 10, but an hour too late

December 16, 2012
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Dark matter top 10, but an hour too late

Well, that’s embarrassing. A little tweak to my dark matter model resulted in a leaderboard score in the top 10. The only problem is that the contest closed about an hour ago. I ran this final prediction earlier today but then simply forgot to go back to it and submit!! On the bright side, I

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Possibly slightly better text analysis with lme4

December 16, 2012
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Possibly slightly better text analysis with lme4

lme4 and its cousin arm are extremely useful for a huge variety of modeling applications (see Gelman and Hill’s book), but today we’re going to do something a little frivolous with them. Namely, we’re going to extend our Denver Debat...

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Making Data Visually Appealing

December 16, 2012
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Making Data Visually Appealing

I’ve recently been considering the graphical presentation of data. I get the feeling that we, ecologists/scientsits, could be better at data presentation. Graphs must be informative, but they don’t have to be ugly. I think that making visually appealing charts … Continue reading →

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