## System Testing

February 28, 2013
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R at Work...crunching numbersIf you wanna find out how your trading idea would have coped in the previous years you would perform a backtest. For years I have used commercial software but could not find a package, which I would really recommend. I have...

## The MaxDiff Killer: Rank-Ordered Logit Models

February 27, 2013
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Compared to MaxDiff (Sawtooth Software), ranked-order logit modeling:simplifies data collection without needing additional software to generate experimental designsreduces respondent burden making the task easier and seemingly ...

## inline 0.3.11

February 27, 2013
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A maintenance release of inline is now on CRAN, and is being uploaded to Debian. The release fixes two minor bugs kindly reported by users. As the two previous releases appear to not have been announced here, their NEWS entries are included as well. ...

## The Paul Tol 21-color salute

February 27, 2013
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You may or may not know that PerformanceAnalytics contains a number of specific color schemes designed for charting data in R (they aren’t documented well, but they show up in some of the chart examples). I’ve been collecting color palates for years in search of good combinations of attractiveness, relative weight, and distinctiveness, helped along

## Graphical Tools (rgl) on a Headless Shiny Server

February 27, 2013
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If you’ve encountered errors such as Warning in rgl.init(initValue) : RGL: unable to open X11 display Warning in fun(libname, pkgname) : error in rgl_init or Error: rgl_dev_getcurrent when trying to use a graphically based package like RGL with Shiny Server, then you’re in the right spot.  The issue is likely that you’re running R or

## Non-Linear Curve Fitting is Nature Publication Worthy?

February 27, 2013
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Someone needs to explain to me why this is a Nature publication ...Granted it is Nature Protocols which started its publication run when I was in grad school and is likely less high-impact as full blown Nature.  Seriously tough - using the So...

## Workshops on Modelling Choices using R in Toronto

February 27, 2013
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Making choices is inherently human. We choose between brands of cereal or amongst candidates in an election. At times, choices may be influenced by the characteristics of the decision maker, such as age, income and sex. Choices may also be influenced by the attributes of competing alternatives, such as the cost of travelling between two cities by air or...

## UPDATE Multiple postgreSQL Table Records in Parellel

February 27, 2013
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Unfortunately the RpostgreSQL package (I’m pretty sure other SQL DBs as well) doesn’t have a provision to UPDATE multiple records (say a whole data.frame) at once or allow placeholders making the UPDATE a one row at a time ordeal, so I built a work around hack to do the job in parellel.  The big problem

February 27, 2013
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On Revolution Analytics partner Cloudera's blog, Uri Laserson has posted an excellent guide to resampling from a large data set in Hadoop. Resampling is an important step in fitting ensemble models (including random forests and other bagging techniques), and Uri provides a step-by-step guide to implementing resampling methods using RHadoop. He provides the complete map-reduce code in the R...

## Installing Pandoc from R (on Windows) – using the {installr} package

February 27, 2013
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The R blogger Rolf Fredheim has recently wrote a great piece called “Reproducible research with R, Knitr, Pandoc and Word“, where he advocates for Pandoc as an essential part of reproducible research workflow in R, in helping to turn documents …Read more »

## Whats new in rugarch (ver 1.01-5)

February 27, 2013
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Since the last release of rugarch on CRAN (ver 1.0-16), there have been many changes and new features in the development version of the package (ver 1.01-5). First, development of the package (and svn) has been moved to google code from r-forge. Second, the package now features exclusive use of xts based time series for

## Fast factor generation with Rcpp

February 27, 2013
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Recall that factors are really just integer vectors with ‘levels’, i.e., character labels that get mapped to each integer in the vector. How can we take an arbitrary character, integer, numeric, or logical vector and coerce it to a factor with Rcpp? It’s actually quite easy with Rcpp sugar: #include <Rcpp.h> using namespace Rcpp; template <int RTYPE> IntegerVector fast_factor_template( const Vector<RTYPE>& x )...

## How to make a scientific result disappear

February 27, 2013
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$How to make a scientific result disappear$

Nathan Danneman (a co-author and one of my graduate students from Emory) recently sent me a New Yorker article from 2010 about the “decline effect,” the tendency for initially promising scientific results to get smaller upon replication. Wikipedia can summarize the phenomenon as well as I can: In his article, Lehrer gives several examples where

## New R Workshop in the Bay Area

February 26, 2013
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Practical Data Visualization with R Saturday March 9th, 2013 8:30-5:00pm EBay 2161 North 1st Street San Jose, California I will be presenting a one day professional development workshop on modern data visualization with R, sponsored by the ACM San Francisco Bay … Continue reading →

## New ways to Hadoop with R

February 26, 2013
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Today, there are two main ways to use Hadoop with R and big data: 1. Use the open-source rmr package to write map-reduce tasks in R (running within the Hadoop cluster - great for data distillation!) 2. Import data from Hadoop to a server running Revolution R Enterprise, via Hbase, ODBC (for high-performance Hadoop/SQL interfaces), or streaming data direct...

## Stop Sign Project Post1: Some GIS stuff done in R

February 26, 2013
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(This article was first published on bRogramming, and kindly contributed to R-bloggers) To leave a comment for the author, please follow the link and comment on their blog: bRogramming. R-bloggers.com offers daily e-mail updates about R news and tutorials on topics such as: Data science, Big Data, R jobs, visualization (ggplot2, Boxplots, maps, animation), programming (RStudio, Sweave, LaTeX, SQL,...

## Job for life ? Bishop of Rome ?

February 26, 2013
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The job of Bishop of Rome – i.e. the Pope – is considered to be a life-long commitment. I mean, it usually was. There have been 266 popes since 32 A.D. (according to http://oce.catholic.com/…): almost all popes have served until their death. But that does not mean that they were in the job for long… One can easily extract...

## Make Your Date Folder Clean with Function unzip & unz

February 26, 2013
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I am a somewhat minimalist R user. I feel uncomfortable if something is not in a good order, such as the names of variables and documents, the structures of my codes and projects. I prefer my data stored in .txt or .csv so I can load them to R using read.table or read.csv. For most of the time we...

## Automatic Notice When Vacancy Available

February 26, 2013
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Today, I visited a webpage inadvertently and found several job positions that I am competent with, unfortunately all of them has expired. How many chances we lost in this way?! So I decide to do somthing to limit this kind of loss, and of course using our smart R! The idea is simple: check the job vacancy webpages reguarly, if...

## The stringdist package

February 26, 2013
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String metrics have important applications in web search, spelling correction and computational biology amongst others. Many different metrics exist, but the most well-known are based on counting the number of basic edit operations it takes to turn one string into … Continue reading →

## First steps of using googleVis on shiny

February 26, 2013
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The guys at RStudio have done a fantastic job with shiny. It is really easy to build web apps with R using shiny. With the help of Joe Cheng from RStudio we figured out a way to make googleVis work on shiny as well. This allows you to make use of the Google Charts...

## Normal distribution functions

February 25, 2013
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Ah, the Central Limit Theorem.  The basis of much of statistical inference and how we get those 95% confidence intervals.  It's just so beautiful!  Lately, I have found myself looking up the normal distribution functions in R.  They...

## What is Revolution R Enterprise?

February 25, 2013
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Let us explain, in 90 seconds: Want a more in-depth introduction to R and Revolution R Enterprise? I'll be giving the webinar Revolution R Enterprise: 100% R and More on March 14. Just follow the link below to secure your seat for the live presentation, and to receive notification of the replay. Revolution Analytics webinars: Revolution R Enterprise: 100%...

## R/ggplot2 tip: aes_string

February 25, 2013
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I’m a big fan of ggplot2. Recently, I ran into a situation which called for a useful feature that I had not used previously: aes_string. Imagine that you have data consisting of observations for several variables – let’s say A, B, C – where each observation is from one of two groups – call them

## The Fun of Error Trapping: R Package Edition

February 25, 2013
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For the last month or so I’ve been working on an R package to make accessing the Adobe (Omniture) Digital Marketing Suite Reporting API easier.  As part of this development effort, I’m at the point where I’m intentionally introducing errors into my function inputs, trying to guess some of the ways useRs might incorrectly input The Fun of...

## Plot 3D Wireframes from Morphologika

February 25, 2013
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Hi morphometricians,A quick update: a function to plot Morphologika 3D wireframes using the package geomorph. This routine (or a version of it) will be included in our next package update under the "read.morphologika" function.Enjoy!Example:library(geo...

## Exporting nice plots in R

February 25, 2013
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It's not always easy getting the right size. The image is CC by Kristina Gill. A vital part of statistics is producing nice plots, an area where R is outstanding. The graphical ablility of R...

## Simplify frequency plots with ggplot in R #rstats

February 25, 2013
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Update March 5th All downloads are now accessible from my script page! Summary This posting shows how to plot frequency plots using the ggplot-package in R. Compared to SPSS standard outputs, you will learn how to create appealing diagrams ready … Weiterlesen →

## Top 6 reasons you need to be using RStudio

February 25, 2013
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Rstudio provides you with tools to make your work more productive.New to R? -  check out these resources for getting staRted. RStudio is an awesome tool that can help you do your work better and faster.  In technical terms...