4157 search results for "git"

Using R to communicate via a socket connection

May 28, 2013
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Occasionally, the need arises to communicate with R via another process. There are packages available to facilitate this communication, but for simple problems, a socket connection may be the answer. Nearly all software languages have a socket communic...

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Value at Risk with exponential smoothing

May 28, 2013
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Value at Risk with exponential smoothing

More accurate than historical, simpler than garch. Previously We’ve discussed exponential smoothing in “Exponential decay models”. The same portfolios were submitted to the same sort of analysis in “A look at historical Value at Risk”. Issue Markets experience volatility clustering.  As the previous post makes clear, historical VaR suffers dramatically from this.  An alternative is … Continue reading...

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Interactive presentation with slidify and googleVis

May 28, 2013
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Interactive presentation with slidify and googleVis

Last week I was invited to give an introduction to googleVis at Lancaster University. This time I decided to use the R package slidify for my talk. Slidify, like knitr, is built on Markdown and makes it very easy to create beautiful HTML5 presentations...

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Updates to the Social Science Starter Kit

May 27, 2013
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The Emacs Social Science Starter Kit is a drop-in collection of packages and settings for Emacs 24 aimed at people like me: that is, people doing social science data analysis and writing, using some combination of tools like R, git, LaTeX, Pandoc, perh...

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Writing a Minimal Working Example (MWE) in R

May 27, 2013
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Writing a Minimal Working Example (MWE) in R

How to Ask for Help using R How to Ask for Help using R The key to getting good help with an R problem is to provide a minimally working reproducible example (MWRE). Making an MWRE is really easy with R, and it will help ensure that...

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Bayesian model II regression

May 27, 2013
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Bayesian model II regression

Regression is a mainstay of ecological and evolutionary data analysis. For example, a disease ecologist may use body size (e.g. a weight from a scale with measurement error) to predict infection. Classical linear regression assumes no error in covariates; they are known exactly. This is rarely the case in ecology, and ignoring error in covariates can bias regression coefficient...

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(Another) introduction to R

May 27, 2013
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(Another) introduction to R

It’s Memorial Day and my dissertation defense is tomorrow. This week I’m phoning in my blog. I had the opportunity to teach a short course last week that was part of a larger workshop focused on ecosystem restoration. A fellow grad student and I taught a session on Excel and R for basic data analysis.

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Combinatorial optimization with gaoptim package

May 27, 2013
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My recent update of gaoptim package brings up a new function, GAPerm, which can be used to perform combinatorial optimization using the Genetic Algorithm approach. The example below solves a TSP instance with 10 points around a circumference, the...

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Creating a presence-absence raster from point data

May 27, 2013
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Creating a presence-absence raster from point data

I’m working on generating species distribution models at the moment for a few hundred species. Which means that I’m trying to automate as many steps as possible in R to avoid having to click buttons hundreds of times in ArcView. … Continue reading →

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BISON USGS species occurrence data

May 27, 2013
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BISON USGS species occurrence data

The USGS recently released a way to search for and get species occurrence records for the USA. The service is called BISON (Biodiversity Information Serving Our Nation). The service has a web interface for human interaction in a browser, and two APIs (application programming interface) to allow machines to interact with their database. One of the...

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