2702 search results for "gis"

plyr and reshape: better, faster, more productive

September 10, 2010
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Hadley Wickham has just released updates to his data-manipulation packages for R, plyr and reshape (now called reshape2), that are much faster and more memory-efficient than the previous incarnations. The reshape2 package lets you flexibly restructure and aggregate data using just three functions (melt, acast and dcast), whereas the plyr package is kind of like a supercharged SQL "GROUP...

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Rcpp 0.8.6

September 10, 2010
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After a somewhat longer than usual break, we now have a new release of Rcpp on CRAN and in Debian. This release adds quite few things. The main one may be the addition of density, distribution, quantile and random number functions for a rather large...

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Rcpp 0.8.6

September 10, 2010
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After a somewhat longer than usual break, we now have a new release of Rcpp on CRAN and in Debian. This release adds quite few things. The main one may be the addition of density, distribution, quantile and random number functions for a rather large n...

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Off to Banff!!

September 9, 2010
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Off to Banff!!

Today I am travelling from Paris to Banff, via Amsterdam and Calgary, to take part in the Hierarchical Bayesian Methods in Ecology two day workshop organised at BIRS by Devin Goodsman (University of Alberta),  François Teste (University of Alberta), and myself. I am very excited both by the opportunity to meet young researchers in ecology

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Webinar September 22: Deploying R

September 8, 2010
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In 2 weeks, on Wednesday September 22, I'll be hosting a webinar in conjunction with Andrew Lampitt at Jaspersoft. This new webinar is all about how to Deploy R: in other words, how to use the new server-based capabilities of Revolution R Enterprise 4 for Linux to embed the results of R scripts into applications and web pages. One...

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Clipping a Surface By a Polygon

September 8, 2010
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Clipping a Surface By a Polygon

Background: A common function in standard GIS software enables users to create a raster surface and extract values or clip it based on a set of polygons. This may be used in cases where you want analysis to be constrained to within a town’s boundaries or a coastline. This tutorial will outline how to create

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Mapping Temperature Anomalies with R

September 3, 2010
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Mapping Temperature Anomalies with R

In this post I show how to map NASA GISS’s  2×2 degree temperature anomaly data using R mapping tools. Rather than rely on a single value to reflect monthly global temperature anomaly, this map shows the anomalies  in each of … Conti...

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Third, and Hopefully Final, Post on Correlated Random Normal Generation (Cholesky Edition)

September 2, 2010
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Third, and Hopefully Final, Post on Correlated Random Normal Generation (Cholesky Edition)

When I did a brief post three days ago I had no plans on writing two more posts on correlated random number generation. But I’ve gotten a couple of emails, a few comments, and some Twitter feedback. In response to my first post, Gappy, calls me out and says, “the way mensches do multivariate (log)normal

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Stochastic approximation in Bristol

September 2, 2010
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Stochastic approximation in Bristol

This is very short notice, but for those in the vicinity and not at the RSS conference, there is a highly interesting workshop taking place in Bristol in ten days (I would certainly have gone, had I not been at the same time in Banff!): We would like to invite you to contribute to our

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Birds of a feather shop together

August 31, 2010
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Birds of a feather shop together

PREDICTING CONSUMER BEHAVIOR FROM SOCIAL NETWORKS This week, Decision Science News is doing a special cross-posting with Messy Matters. The post below is by Sharad Goel and describes work that he and your Decision Science News editor Dan Goldstein are jointly undertaking at Yahoo! Do you know what the #$*! your social media strategy is?

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