4157 search results for "git"

BISON USGS species occurrence data

May 27, 2013
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BISON USGS species occurrence data

The USGS recently released a way to search for and get species occurrence records for the USA. The service is called BISON (Biodiversity Information Serving Our Nation). The service has a web interface for human interaction in a browser, and two APIs (application programming interface) to allow machines to interact with their database. One of the...

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Using R to visualize geo optimization algorithms

May 26, 2013
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Using R to visualize geo optimization algorithms

Site optimization is the process of finding an optimal location for a plant or a warehouse to minimize transportation costs and duration. A simple model only consists of one good and no restrictions regarding transportation capacities or delivery time. The optimizing algorithms are often hard to understand. Fortunately, R is a great tool to make them more comprehensible.The basic...

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Sentiment analysis finds trouble in the Enron emails

May 24, 2013
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Sentiment analysis finds trouble in the Enron emails

The Enron email dataset, collected during the FERC investigation of the Enron financial scandal, represents the largest publicly available set of emails. This makes theman ideal testbed for sentiment analysis algorithms. Ikanow's Andrew Strite used the open-source Infinit.e framework and a Hadoop cluster to generate sentiment scores for all of the Enron emails, and then used R to manipulate...

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Compiling R from Source with OpenMP, Accelerate and MKL in OS X

May 24, 2013
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Compiling R from Source in OS X I set out to find out whether I could speed up R by compiling it from source and: using Apple´s Accelerate Framework enabling OpenMP (which is disabled under OS X and Windows by default, but enabled under Linux) using Intel´s Intel´s Math Kernel Library I also wanted to know how an implicit parallel library,...

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Working with shapefiles, projections and world maps in ggplot

May 23, 2013
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Working with shapefiles, projections and world maps in ggplot

In this post I show some different examples of how to work with map projections and how to plot the maps using ggplot. Many maps that are using the default projection are shown in the longlat-format, which is far from optimal. Here I show how to use either the Robinson or Winkel Tripel projection. Read more

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Generating a Markov chain vs. computing the transition matrix

May 23, 2013
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Generating a Markov chain vs. computing the transition matrix

A couple of days ago, we had a quick chat on Karl Broman‘s blog, about snakes and ladders (see http://kbroman.wordpress.com/…) with Karl and Corey (see http://bayesianbiologist.com/….), and the use of Markov Chain. I do believe that this application is truly awesome: the example is understandable by anyone, and computations (almost any kind, from what we’ve tried) are easy to perform....

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The R-Podcast Episode 13: Interview with Yihui Xie

May 23, 2013
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It’s an episode of firsts on the R-Podcast! In this episode recorded on location I had the honor and privilege of interviewing Yihui Xie, author of many innovative packages such as knitr and animation. Some of the topics we discussed include: Yihui’s motivation for creating knitr and some key new features How markdown plays a

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What happened to six million voters?

May 22, 2013
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What happened to six million voters?

The recent elections in Pakistan on May 11 were a great success by all means. In spite of the threats for violence by Al-Qaeda and its local franchises in Pakistan against those who would vote, millions of Pakistanis indeed stepped out to vote for an elected government. The Election Commission of Pakistan (ECP) claimed a voter turnout of 60%....

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Analytical and simulation-based power analyses for mixed-design ANOVAs

May 21, 2013
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Analytical and simulation-based power analyses for mixed-design ANOVAs

In this post I show some R-examples on how to perform power analyses for mixed-design ANOVAs. The first example is analytical—and adapted from formulas used in G*Power (Faul et al., 2007), and the second example is a Monte Carlo simulation. Read more

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Geolocate IP addresses in R

May 20, 2013
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Geolocate IP addresses in R

This R function uses the free freegeoip.net geocoding service to resolve an IP address (or a vector of them) into country, region, city, zip, latitude, longitude, area and metro codes. Continue reading →

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