2645 search results for "GIS"

Parallel R Model Prediction Building and Analytics

January 26, 2012
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Modifying R code to run in parallel can lead to huge performance gains. Although a significant amount of code can easily be run in parallel, there are some learning techniques, such as the Support Vector Machine, that cannot be easily parallelized. However, there is an often overlooked way to speed up these and other models. It involves executing the...

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Geocode your data using, R, JSON and Google Maps’ Geocoding APIs

January 24, 2012
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Over the last year and half, I have faced numerous challenges with geocoding the data that I have used to showcase my passion for location analytics.  In 2012, I decided to take thing in my control and turned to R.  Here, I am sharing a simpl...

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ACT to SAT M+V Concordance Chart in R

January 23, 2012
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For those of who work in Enrollment Management and routinely analyze higher ed data, I wanted to share an easy way to convert ACT to equivalent SAT M+V scores in R. I am dynamically building a dataset that uses the concordance chart located here. Simply, use this data frame and merge it onto your existing

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My first R package: parallel differential evolution

January 23, 2012
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My first R package: parallel differential evolution

Last night I was working on a difficult optimization problems, using the wonderful DEoptim package for R. Unfortunately, the optimization was taking a long time, so I thought I'd speed it up using a foreach loop, which resulted in the fo...

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Cluster your Facebook friends

January 22, 2012
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Cluster your Facebook friends

Last week, I came across two interesting posts by Romain François and Petr Simecek: Crawling Facebook with R, in which Romain explains how to connect to the Facebook Graph API Mining Facebook Data: Most “Liked” Status and Friendship Network, in which Petr use Romain’s function to visualize your friend’s network. As coincidence would have it, I also came across an...

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A Quick View Over a MASHe Google Spreadsheet Twitter Archive of UKGC12 Tweets

January 20, 2012
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A Quick View Over a MASHe Google Spreadsheet Twitter Archive of UKGC12 Tweets

Following on from A Tool Chain for Plotting Twitter Archive Retweet Graphs – Py, R, Gephi, here’s a quick view summary view over #UKGC12 tweets saved in Google Spreadsheet archive as developed by Martin Hawksey, generated from an R script (R code available here; #ukgc12 tweet archive here)… (I did mean to tidy these up,

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Object Oriented Programming in R

January 20, 2012
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As someone who was a Java programmer for many years learning R’s object oriented programming framework has been frustrating to say the least. I like the simplicity of S3 but find it limiting when you wish to write methods that change the underlying data elements. That is, printing, summarizing, and plotting work great because they

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Hadley Wickham goes behind the scenes on ggplot2

January 20, 2012
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Hadley Wickham goes behind the scenes on ggplot2

Hadley Wickham, creator of the ggplot2 packages for R (as well as several others) will present a webinar on February 8 going behind the scenes of the popular graphics package. If you've never used ggplot2 before, this will be a great way to learn about the kinds of charts you can create with it; and if you're a regular...

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Power and Sample Size for Repeated Measures ANOVA with R

January 20, 2012
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Power and Sample Size for Repeated Measures ANOVA with R

Background One of my colleagues is an academic physical therapist (PT), and he's working on a paper to his colleagues related to power, sample size, and navigating the thicket of trouble that surrounds those two things. We recently got together to walk through some of the issues, and I thought I would share some of the wildlife we observed...

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Knitr is Awesome!

January 19, 2012
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I love TikZ in LaTeX and I use it exclusively when writing figures for my papers. I also use the tikzDevice package to convert all figures I create in R to TikZ code, so the font used in the text and figures is the same (and having your R figures in Ti...

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