2730 search results for "GIS"

Performance with foreach, doSNOW, and snowfall

June 13, 2012
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Is it just me, or does the performance of the foreach package with a doSNOW backend operating on a socket grid suck?Here at work, I am helping to setup a cluster of Windows machines for distributed R processing.  We have lots of researchers runnin...

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In case you missed it: May 2012 Roundup

June 13, 2012
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In case you missed them, here are some articles from May of particular interest to R users. R tops the annual KDNuggets Data Mining Software poll for the first time. R 2.15.1 is scheduled for June 22. (Revolution R Enterprise 6, released on June 5, is based on 2.14.2.) A tutorial uses R, Hadoop, and the RHadoop project to...

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Simple network diagrams in R

June 12, 2012
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Simple network diagrams in R

Why study networks? Development and aid projects these days are more and more often focussing on supporting networks, so tools to analyse networks are always welcome. In this post I am going to present a very easy-to-use package for the stat...

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Simple network diagrams in R

June 12, 2012
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Simple network diagrams in R

Why study networks? Development and aid projects these days are more and more often focussing on supporting networks, so tools to analyse networks are always welcome. In this post I am going to present a very easy-to-use package for the stats program R which makes nice-looking graphs of these kinds of networks. In a recent

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Statistics of Drawdown–paper and post

June 11, 2012
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Statistics of Drawdown–paper and post

Thank so much to Patrick Burns’ post Variability in maximum drawdown.  He starts with “Maximum drawdown is blazingly variable,” which I say is why money management is so blazingly difficult.  After spending a lot of time thinking about ...

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Time series cross-validation 4: forecasting the S&P 500

June 11, 2012
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Time series cross-validation 4: forecasting the S&P 500

I finally got around to publishing my time series cross-validation package to github, and I plan to push it out to CRAN  shortly. You can clone the repo using github for mac, for windows, or linux, and then run the following script to...

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Simulating Euro 2012

June 11, 2012
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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

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Classifying the UCI mushrooms

In my last post, I considered the shifts in two interestingness measures as possible tools for selecting variables in classification problems.  Specifically, I considered the Gini and Shannon interestingness measures applied to the 22 categorical mushroom characteristics from the UCI mushroom dataset.  The proposed variable selection strategy was to compare these values when computed from only edible mushrooms...

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Testing recommender systems in R

June 10, 2012
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Testing recommender systems in R

Recommender systems are pervasive. You have encountered them while buying a book on barnesandnoble, renting a movie on Netflix, listening to music on Pandora, to finding the bar visit (FourSquare). Saar for Revolution Analytics, had demonstrated how to get started with some techniques for R here. We will build some using Michael Hahsler’s excellent package

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ggplot2: Creating a custom plot with two different geoms

June 9, 2012
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ggplot2: Creating a custom plot with two different geoms

This past week for work I had to create some plots to show the max, min, and median of a measure across the levels of a qualitative variable, and show the max and min of the same variable within a … Continue reading →

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