VCI — The Value Charts Indicator

August 23, 2014
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VCI — The Value Charts Indicator

So recently, I was made known of the Value Charts Indicator , which was supposed to be some form of … Continue reading →

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R OOP – a little privacy please?

August 23, 2014
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As of late, I’ve been making heavy use of Reference Classes in R. They are easier for me to wrap my mind around since they adopt a usage style more like “traditional” OOP languages like Java. Primarily, object methods are part of the class definition and accessed via the instantiated object. For instance: With S3/S4 classes, you...

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An adverse consequence of fitting "maximal" linear mixed models

August 23, 2014
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An adverse consequence of fitting "maximal" linear mixed models

Distribution of intercept-slope correlation estimates with 37 subjects, 15 itemsDistribution of intercept-slope correlation estimates with 50 subjects, 30 itemsShould one always fit a full variance covariance matrix (a "maximal" model) when one analyze...

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More ESA 2014 Program Text-Mining: Topics as Communities

August 22, 2014
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More ESA 2014 Program Text-Mining: Topics as Communities

In my first pass at text analysis of the ESA program, I looked at how the frequency of words used in the ESA program differed from last year to this year. There are much more sophisticated ways at looking at word use in text, though, and I began to dive into the text-mining literature to find...

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Because it’s Friday: A 3-minute movie in 4095 bytes

August 22, 2014
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This entire movie — images, music, everything — is generated from a Windows PC executable of just 4,095 bytes. That's not a typo: we're not talking bytes not megabytes or gigabytes here. Less than 4kb total creates this entire scene. For comparison, a medium-quality video file of this exact same scene in AVI format comes in at over 64Mb:...

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Entering the field as a data scientist with certification

August 22, 2014
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By Neera Talbert, VP Services and Ben Wiley, R Programmer at Revolution Analytics By now, everyone should be familiar with the data scientist boom. Simply logging onto LinkedIn reveals a seemingly infinite number of people with words and phrases like “Data Scientist”, “Big Data Specialist”, and “Analytics” in their title. A few weeks ago, an article floated around the...

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Pro Grammar and Devel Hoper

August 22, 2014
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Pro Grammar and Devel Hoper

I've been teasing about this post for some time now. My next blog post is "Pro Grammar and Devel Hoper". And this not just an empty pun. Stay tuned.— Romain François (@romain_francois) August 3, 2014 @stefanbache another teaser. https://t.co/i2ubfOyjIO iris >> filter( Sepal.Length > 7 ) iris |> filter( Sepal.Length > 7 )— Romain François (@romain_francois)

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Running “Native” Data Wrangling Applications in the Browser – IPython Notebooks (and R?) in Chrome

August 22, 2014
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Running “Native” Data Wrangling Applications in the Browser – IPython Notebooks (and R?) in Chrome

Using browser based data analysis toolkits such as pandas in IPython notebooks, or R in RStudio, means you need to have access to python or R and the corresponding application server either on your own computer, or running on a remote server that you have access to. When running occasional training sessions or workshops, this

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stringdist 0.8: now with soundex

August 22, 2014
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An update to the stringdist package was released earlier this month. Thanks to a contribution of Jan van der Laan the package now includes a method to compute soundex codes as defined here. Briefly, soundex encoding aims to translate words … Continue reading →

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RcppEigen 0.3.2.2.0

August 21, 2014
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A new upstream release of the Eigen C++ template library for linear algebra was released a few days ago. And Yixuan Qiu did some really nice work rolling this into a new RcppEigen released and then sent me a nice pull requent. The new version is now...

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R in Production – Panel Discussion – LA R meetup @ useR! 2014

August 21, 2014
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(Please click here if the video above doesn’t load.) The video above is from an event...

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R in Production – Opening Talk by Yasmin Lucero – LA R meetup @ useR! 2014

August 21, 2014
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(Please click here if the video above doesn’t load.) During useR! 2014, the LA R...

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Revolution Analytics’ User Group Map Contest has a Winner

August 21, 2014
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by Joseph Rickert We are pleased to announce that Jo-fai Chow is the winner of the Revolution Analytics contest. Jo-fai’s entry, which was implemented as a Shiny project, may be viewed by clicking on the figure below. Jo-fai’s work not only produced an aesthetically pleasing sequence of maps but also provides a superb example of a well-documented, small project...

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Extracting Latent Variables from Rating Scales: Factor Analysis vs. Nonnegative Matrix Factorization

August 21, 2014
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Extracting Latent Variables from Rating Scales: Factor Analysis vs. Nonnegative Matrix Factorization

For many of us, factor analysis provides a gateway to learning how to run and interpret nonnegative matrix factorization (NMF). This post will analyze a set of ratings on a 218 item adjective checklist using both principal axis factor analysis and NMF....

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Announcing dtupdate v1.0 – R Package Reporter/Updater for the devtools Universe

August 21, 2014
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The dtupdate package has functions that attempt to figure out which packages have non-CRAN versions (currently only looks for github ones) and then tries to figure out which ones have updates (i.e. the github version is > local version). It provides an option (not recommended) to auto-update any packages with newer development versions. The reason auto updating is...

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Optimizing with R expressions

August 21, 2014
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Optimizing with R expressions

I recently discovered a powerful use for R expression()’sSay you are trying to fit some experimental data to the following nonlinear equation: Ky0eu(x−tl)K+y0(eu∗(x−tl)−1)+b1+(b0−b1)e−kx+b2x with the independent variable x using nlminb() as the minimization optimizer.This sort of work is significantly improved (i.e. faster with better convergence) if an analytical gradient vector and a Hessian matrix for the objective function are provided....

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For Loop Tracking (Windows Progress Bar)

For Loop Tracking (Windows Progress Bar)

I know that many people consider for-loops the devil, but every so often I get lazy and I use them in the office.  Sometimes it’s nice to keep track of how far through the loop R has gone.  A couple years … Continue reading →

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googleVis!!!

August 20, 2014
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googleVis!!!

I'm back working on R&graphics at last. I've made some progress on the shiny+rgl front, but haven't really had the time to create anything which could be posted here... However, it's been a while, so today I thought I'd take advantage of the releas...

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Open iTerm (OS X) to a Directory from R

August 20, 2014
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Sometimes you need to get to a command prompt from R, whether it’s to wrangle git on the command line or do some package work. RStudio provides ways to do this from menus and hotkeys, but on OS X it sticks you in Terminal.app. I’m an iTerm user—and, I really prefer being in that app vs the one...

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How to integrate R with your calendar

August 20, 2014
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How to integrate R with your calendar

Hilary Parker has contributed a lovely article to Significance, the magazine of the American Statistical Association and the Royal Statistical Society, on using R to set your Google calendar to mark the time of sunsets. Hilary details the process in the article, but the basic idea is to use the sunrise.set function from the StreamMetabolism package to calculate sunset...

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Do your "data janitor work" like a boss with dplyr

August 20, 2014
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Do your "data janitor work" like a boss with dplyr

Data “janitor-work” The New York Times recently ran a piece on wrangling and cleaning data: “For Big-Data Scientists, ‘Janitor Work’ Is Key Hurdle to Insights” Whether you call it “janitor-work,” wrangling/munging, cleaning/cleansing/scrubbing, tidying, or something else, the article above is worth a read (even though it implicitly denigrates the important work that your housekeeping staff does). It’s...

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R Passes SPSS in Scholarly Use, Stata Growing Rapidly

August 19, 2014
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R Passes SPSS in Scholarly Use, Stata Growing Rapidly

by Robert A. Muenchen Here is my latest update to The Popularity of Data Analysis Software. To save you the trouble of reading all 25 pages of that article, the new section is below. The two most interesting nuggets it contains are: … Continue reading →

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dplyr: A gamechanger for data manipulation in R

August 19, 2014
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I demonstrate how to use dplyr for data manipulation in R (R code and data on GitHub ). I had heard of the package before and finally gave it a try after attending Hadley Wickham's presentation at useR! in LA a couple of months ago. dplyr will change y...

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GBMs are awesome: Part I

August 19, 2014
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GBMs have become my favorite type of model over the last two years. In this tutorial, I demonstrate how to use a GBM for binary classification in R (predicting whether an event occurs or not). I also discuss basic model tuning and model inference with ...

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RcppArmadillo 0.4.400.0

August 19, 2014
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After two pre-releases in the last few days, Conrad finalised a new Armadillo version 4.400 today. I had kept up with the pre-releases, tested twice against all eighty (!!) CRAN dependents of RcppArmadillo and have hence uploaded RcppArmadillo 0.4....

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I like you and you like me…but what does it all mean. (Part 1)

August 19, 2014
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I like you and you like me…but what does it all mean. (Part 1)

Tinder is a popular matchmaking application that allows users to connect with others whom they share a physical attraction. New members build their profile by importing their age, gender, geographic information, and photos from their Facebook account. Users are then presented with profiles which meet their search criteria and are able to like or dislike them. Unlike traditional online

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Recent Articles

August 19, 2014
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Recent Articles

  I have uploaded a few papers I have written and presented at some national conferences over the past several years.  Currently, all the articles relate to election research.

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CRAN release jsonlite 0.9.10 (RC)

August 19, 2014
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CRAN release jsonlite 0.9.10 (RC)

The jsonlite package is a JSON parser/generator optimized for the web. It implements a bidirectional mapping between JSON data and the most important R data types. This is very powerful for interacting with web APIs, or to build pipelines where...

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Integrating R with production systems using an HTTP API

August 19, 2014
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Integrating R with production systems using an HTTP API

by Nick Elprin, Co-Founder of Domino Data Lab We built a platform that lets analysts deploy R code to an HTTP server with one click, and we describe it in detail below. If you have ever wanted to invoke your R model with a simple HTTP call, without dealing with any infrastructure setup or asking for help from developers...

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