## An economist explains: Why I use R

May 10, 2010
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Economist and R blogger JD Long gave a talk last week (as part of the vconf.org project) about why he uses R to do statistical forecasts of agricultural yield for the reinsurance company he works for. I couldn't make the live session, but a replay is now available. The audio's a bit choppy, but if you've every struggled with...

## ggplot2: Waterfall Charts

May 10, 2010
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Waterfall charts are often used for analytical purposes in the business setting to show the effect of sequentially introduced negative and/or positive values. Sometimes waterfall charts are also referred to as cascade charts. In the next few paragraphs I will show how to plot a waterfall chart using ggplot2. Data A very small fictional dataset

## Abbreviations of R Commands Explained: 250+ R Abbreviations

May 10, 2010
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The R programming language includes many abbreviations. Abbreviations exist in function names, argument names, and allowed values for arguments. This post expands on over 150 R abbreviations with the aim of making it easier for users new to R who are trying...

## Abbreviations of R Commands Explained: 250+ R Abbreviations

May 10, 2010
By

The R programming language includes many abbreviations. Abbreviations exist in function names, argument names, and allowed values for arguments. This post expands on over 150 R abbreviations with the aim of making it easier for users new to R who are trying...

## Book Review – Modern Applied Statistics with S by W. N. Venables and B. D. Ripley (Springer 2003)

May 9, 2010
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Order this book from Amazon Modern Applied Statistics with S (Fourth Edition) is one of the oldest and most popular books on Applied Statistics using R and S-plus. A large number of topics in Applied Statistics are covered in this book and it is certainly not for the faint hearted. A sound knowledge of

## Computational Statistics

May 9, 2010
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Do not resort to Monte Carlo methods unnecessarily. When I received this 2009 Springer-Verlag book, Computational Statistics, by James Gentle a while ago, I briefly took a look at the table of contents and decided to have a better look later… Now that I have gone through the whole book, I can write a short

## Sweave with Emacs and ESS, problem solved!

May 9, 2010
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With help from Seb, the nagging problem I had when trying to sweaving with Emacs and ESS (http://old.nabble.com/ESS-and-Sweave-td28339734.html) has been solved.First of all, apply the patch for ess-swv.el, provided by Seb. Second, set the default ...

## Using the update function during variable selection

May 9, 2010
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When fitting statistical models to data where there are multiple variables we are often interested in adding or removing terms from our model and in cases where there are a large number of terms it can be quicker to use the update function to start with a formula from a model that we have already

## Forsythe’s algorithm

May 8, 2010
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$Forsythe’s algorithm$

In connection with the Bernoulli factory post of last week, Richard Brent arXived a short historical note recalling George Forsythe’s algorithm for simulating variables with density when (the extension to any upper bound is straightforward). The idea is to avoid computing the exponential function by simulating uniforms until since the probability of this event is

## Basket Option Pricing: Step by Step

May 8, 2010
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$Basket Option Pricing: Step by Step$

I find options fascinating because they deal with the abstract ideas of volatility and correlation, both of which are unobservable and can often seem like wild animal spirits (take the current stock market as an example). Understanding these subtle concepts is never easy, but it is essential in pricing some of the more exotic

## Initial Post

May 8, 2010
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As a web application and database developer who has spent most of my time in the world Java, Ruby, Python and SQL, the R language has some unfamiliar functionality.This blog will be comprised of tips and tricks for making charts with the R language.

## Connecting R and Python

May 7, 2010
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There are a few ways to do this, but the only one that worked for me was to use Rserve and rconnect. In R, do this: 1 2 3 install.packages("Rserve") library(Rserve) Rserve(debug = FALSE, port=6311, args=NULL) Then you can connect in Python very easily. Here is a test in Python: 1 2 rcmd = pyRserve.rconnect(host='localhost', port=6311) print(rcmd('rnorm(100)'))

May 7, 2010
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As part of all the news from yesterday, we also announced our vision and roadmap for the Revolution R product line for 2010. You can see a short summary of our vision in this two-minute video, or see more details in the roadmap whitepaper available for download. But here's a quick overview of our plans: First, we intend to...

## Knowing whether a time-series has been differenced appropriately in order to make it stationary

May 7, 2010
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Hello everybody,Today I would like to make you learn a simple method (and of-course using R) how to identify whether a time-series has been differenced appropriately while making it stationary.Suppose, you have made a series stationary by differencing it, now in order to know whether it is neither over nor under differenced subject the current series against next level...

## Knowing whether a time-series has been differenced appropriately in order to make it stationary

May 7, 2010
By

Hello everybody,Today I would like to make you learn a simple method (and of-course using R) how to identify whether a time-series has been differenced appropriately while making it stationary.Suppose, you have made a series stationary by differencing it, now in order to know whether it is neither over nor under differenced subject the current series against next level...

## A new site for the R community: inside-R.org

May 6, 2010
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We've just launched a beta/preview of a new website for the R community, inside-R.org. The site is sponsored by Revolution Analytics (who funded its development and maintenance), but it's designed for anyone who uses or has in an interest in the R Project generally. So, you might ask, why another community site for R, when there's already several R...

## Bayes vs. SAS

May 6, 2010
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Glancing perchance at the back of my Amstat News, I was intrigued by the SAS advertisement Bayesian Methods Specify Bayesian analysis for ANOVA, logistic regression, Poisson regression, accelerated failure time models and Cox regression through the GENMOD, LIFEREG and PHREG procedures. Analyze a wider variety of models with the MCMC procedure, a general purpose Bayesian

## R: choose file dialog box

May 6, 2010
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Needed this one recently, it pops up a window to pick a file to be used by r, then reads the contents into myData: myFile

## How I came to R

May 6, 2010
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J. D. Long will be giving an introduction to R - how he got into it when doing data analysis and what drew him to use it instead of complicated excel models.

## Revolution R Enterprise now free to academics

May 6, 2010
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Unlike Revolution R Community which is 100% free to everyone, our commercial-grade Revolution R Enterprise distribution bundles R with proprietary components from our development team, which are normally available only to paying subscribers. (Those subscriptions are the way we get income to keep the company going.) Those components include our full ParallelR libraries for parallel programming, enhanced for 64-bit...

## Exporting R output to MS-Word with R2wd (an example session)

May 6, 2010
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Creating reports is one of the basic tasks in data analysis. R provides numerous functions and packages to export it’s (beautiful) output and help compile it into a report. In this post I will present one such (basic) solution for Windows OS users for exporting R output into Microsoft Word using the R2wd (package). There are more ways and...

## REvolution Computing is now Revolution Analytics

May 6, 2010
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So, as you may have noticed from the new banner here at the blog, we've changed our name to Revolution Analytics. It's still the same company and the same people, and still focused around the R Project, but now with a fresh new look and lots of exciting news. I'll be blogging about our new academic program, our new...

## R is like Ruby

May 6, 2010
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There are many similarities between R and Ruby. - Learning both has been fun - "dude, i'm playing with R and love it." The excitement doesn't end!I'm totally addicted. - I keep discovering new and nifty things. Every time I hit an interesting pr...

## Mixed linear model approach adapted for genome-wide association studies

May 6, 2010
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A few weeks ago I covered an R package for efficient mixed model regression that is capable of simultaneously accounting for both population stratification and relatedness to compute unbiased estimates of standard errors and p-values for genetic associ...

## Rearranging definitions in R

May 6, 2010
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I came up with a handy little trick for programming in R. I like to define a lot of variables all at once without worrying about what order they’re in. The goal would be something like this: K  = -R2/R1 … Continue reading →

## Candy branching process

May 5, 2010
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$Candy branching process$

The mathematical puzzle in the latest weekend edition of Le Monde is as follows: Two kids are given three boxes of chocolates with a total of 32 pieces. Rather than sharing evenly, they play the following game: Each in turn, they pick one of the three boxes, empty its contents in a jar and pick

## Game of Life in R

May 5, 2010
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Before I decided to learn R in a serious way, I thought about learning Flash/Actionscript instead. Most of my work involves evolutionary models that take place over time. I need visual representations of change. It’s certainly possible to represent change and tell an evolving story with a single plot (see for example Tufte’s favorite infographic),

## 13 videos for learning R

May 5, 2010
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Jeromy Anglim has just posted a nice round-up of instructional videos for learning R. The videos are categorized into four levels: What is R? Introductory R? Intermediate and Advanced Materials on R and Related Resources (including a link to written resources for getting started with R). Check out all the links at Jeromy's post, linked below. Jeromy Anglim's blog:...