2645 search results for "gis"

Ack! Duplicates in the Data!

May 3, 2012
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Ack!  Duplicates in the Data!

As I mentioned in a previous post, I compiled the data set that I’m currently working on in PostgreSQL.  To get this massive data set, I had to write a query that was massive by dint of the number of … Continue reading →

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RegEx: Named Capture in R

May 3, 2012
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I consider myself a decent RegEx user.  References to famous quotes about RegEx aside, I find it intuitive, like its speed and that it makes my code simple (more so than the alternative anyhow). Thus, I use RegEx where I can in the growing grab bag of languages I consider myself proficient in: *nix command line / shell scripts Javascript PHP Matlab Python R Now...

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How to plot three categorical variables and one continuous variable using ggplot2

May 3, 2012
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How to plot three categorical variables and one continuous variable using ggplot2

This post shows how to produce a plot involving three categorical variables and one continuous variable using ggplot2 in R. The following code is also available as a gist on github. 1. Create Data First, let's load ggplot2 and create some data to work...

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EU rules that computer languages cannot be copyrighted

May 2, 2012
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EU rules that computer languages cannot be copyrighted

The European Court of Justice has published its decision in SAS v WPL; the title of the press release says it all “The functionality of a computer program and the programming language cannot be protected by copyright”. To summarise the background, World Programming Ltd developed a system that was capable of emulating the input/output behavior

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Speeding up R with Intel’s Math Kernel Library (MKL)

May 2, 2012
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Speeding up R with Intel’s Math Kernel Library (MKL)

I did some comparisons of the generic BLAS with Intel's MKL (both sequential and parallel) on a Dell PowerEdge 610 server with dual hyperthreading 6-core 3.06GHz Xeon X5675 processors.  Here are the results from an R benchmarking script (Normal R ...

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Speeding up R with Intel’s Math Kernel Library (MKL)

May 2, 2012
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I did some comparisons of the generic BLAS with Intel's MKL (both sequential and parallel) on a Dell PowerEdge 610 server with dual hyperthreading 6-core 3.06GHz Xeon X5675 processors.  Here are the results from an R benchmarking script (Normal R indicates the generic BLAS,  sMKL is the sequential (single core Intel MKL, and pMKL is the parallel Intel MKL using...

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A gallery view for Craigslist

May 1, 2012
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A gallery view for Craigslist

As much as I love Craigslist, I sometimes find the interface a bit limited. My biggest wish? That there was an option for showing the search results as an image gallery, like eBay has. This could prove quite useful for browsing things like antiques,...

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Mining for relations between nominal variables

May 1, 2012
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Mining for relations between nominal variables

The task today was to find what variables had significant relations with an important grouping variable in the big dataset I’ve been working with lately.  The grouping variable has 3 levels, and represents different behaviours of interest.  At first I … Continue reading →

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NSF BIGDATA webinar

May 1, 2012
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If you're doing any kind of big data analysis - genomics, transcriptomics, proteomics, bioinformatics - then unless you've been on vacation the last few weeks you've no doubt heard about the NSF/NIH BIGDATA  Initiative (here's the NSF solicitation...

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French Global Factors

April 30, 2012
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French Global Factors

I have said it already in multiple posts, but Kenneth French’s data library is one of the most generous and powerful contributions to the financial community.  To build on Systematic Investor’s series on factors, I thought I should run some ba...

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