2721 search results for "GIS"

I Work For The Internet !

December 13, 2011
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I Work For The Internet !

UPDATE: code and figure updated at 647 AM CST on 19 Dec '11.  Also, see Jarrett Byrnes (improved) fork of my gist  here.The site I WORK FOR THE INTERNET is collecting pictures and first names (last name initials only) to show collective suppo...

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Teaching Assistant with R expertise needed in Toronto

December 12, 2011
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Services of a teaching assistant (TA) are required for a course in Applied Retail Research at Ryerson University in Toronto. The course will run from January to April 2012. Experience with statistical analysis  using R is required. For details on the course, please click HERE. To apply or read more about the position, please

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Default Convenience Functions in R (Rprofile.site)

December 12, 2011
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Default Convenience Functions in R (Rprofile.site)

I keep my blog-reference-functions, snippets, etc., at github and want to source them from there. This can be achieved by utilizing a function (source_https, customized for my purpose HERE). The original function was provided by the R-Blogger Tony Brey...

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Time series cross-validation 3

December 12, 2011
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Time series cross-validation 3

I've updated my time-series cross validation algorithm to fix some bugs and allow for a possible xreg term.     This allows for cross-validation of multivariate models, so long as they are specified as a function with the following ...

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Exploring Your Voter File with R

December 12, 2011
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Exploring Your Voter File with R

We perform a voter file analysis for Wake County, NC using R.

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Using R to create a logo: Simple

December 9, 2011
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Using R to create a logo: Simple

R user Josh Reich, who we've featured here on the blog before, is also the CEO and co-founder of the new user-friendly bank, Simple. (Confidential to Josh -- still waiting on my invite...). So it's no suprise that Simple's logo is rendered using the R language: wave <- function (a, R, p, w) { x <- (0.5 + 0.5*R*sin(p+w*a))*cos(a)...

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A Tale of Two Frontiers

December 9, 2011
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A Tale of Two Frontiers

In a follow up to Evolving Domestic Frontier, I wanted to explore the efficient frontier including international indexes since 1980.  Life is great when your primary indexes (Barclays Aggregate and S&P 500) lie on the frontier as they did 1980...

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Stability of classification trees

December 9, 2011
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Stability of classification trees

Classification trees are known to be unstable with respect to training data. Recently I have read an article on stability of classification trees by Briand et al. (2009). They propose a quantitative similarity measure between two trees. The method is i...

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Running your R and LaTeX Infrastructure from a portable USB Drive

December 9, 2011
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Running your R and LaTeX Infrastructure from a portable USB Drive

On my road to eventually running all of my programs off an USB device I’ve gotten a little bit closer yesterday thanks to input from Duncan Murdoch and Yihui Xie. Eventually running the entire Windows OS off a USB drive would be nice (not talking about running it as a Virtual Machine, but to have … Continue reading...

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MCMC chain analysis and convergence diagnostics with coda in R

December 9, 2011
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MCMC chain analysis and convergence diagnostics with coda in R

Last week, I gave a seminar about MCMC chain analysis and convergence diagnostics with coda in R, and I thought a summary would make a nice post. As a prerequisite, we will use a few lines of code, very similar to a previous post on MCMC sampling. In the code, we create some test data…

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