Storing package data in custom environments If you do R package development, sometimes you want to be able to store variables specific to your package, without cluttering up the users workspace. One way to do this is by modifying the global options. This is done by packages grDevices and parallel. Sometimes this doesn't seem to work quite right (see this...
Down-Sampling Using Random Forests
We discuss dealing with large class imbalances in Chapter 16. One approach is to sample the training set to coerce a more balanced class distribution. We discuss down-sampling: sample the...
Sentence Drawing: Function vs. Art
I recently was reading the book “Functional Art” and came across the work of Stefanie Posavec. Her Sentence Drawings (click here to see and click here to learn) caught...
Comparing mnlogit and mlogit for discrete choice models
Earlier this weekend (Dec. 7, 2013), mnlogit was released on CRAN by Wang Zhiyu and Asad Hasan ([email protected]) claiming that mnlogit uses “parallel C++ library to achieve fast computation of...
Tim Hortons Density
Tim Hortons Density Inspired by this post, I wanted to examine the locations and density of Tim Hortons restaurants in Canada. Using Stats Canada data, each census tract is...
amazonly associated thanks (& warnin’)
Following a now well-established pattern, let me (re)warn (the few) unwary ‘Og readers that the links to Amazon.com and to Amazon.fr found on this blog are actually susceptible to...
The forestplot of dreams
Displaying large regression models without overwhelming the reader can be challenging. I believe that forestplots are amazingly well suited for this. The plot gives a quick understanding of the...
Fukushima region radiation decrease
Fukushima is still a topic which gets headlines, and somewhere in a comment was a link to actual and historical radiation data: Fukushima prefecture radioactivity measurement map. It...
R Interface for Teaching
R Interface for Teaching Kaitlin Thaney asked on Twitter last week about using Ramnath Vaidyanathan's new interactive R notebook 1 2 for teaching. Liking the look of...
R and Big Data at Big Data Summit at UI Research Park
I spent yesterday at the very enjoyable Big Data Summit held at the University of Illinois Research Park at the edge of the University of Illinois at Urbana-Champaign. campus. My (short) presentation was...
24 Days of R: Day 7
Carrying on from the last post, I'm going to take a closer look at election results for the 2012 US presidential election in North Carolina. This state's 15 electoral...
Random points on the Earth
The problem with puzzles is that you keep it in your head for days, until you find an answer. Or at least some ideas about a possible answer. This...
An Animation of the t Distribution as a Mixture of Normals
You’ve probably heard about the t distribution. One good use for this distribution is as an alternative to the normal distribution that is more robust against outliers. But where...
Fall is the data analysis season
Dear diary, I spent a lot of my summer in the lab, and my fall has been mostly data analysis, with a little writing and a couple of courses...
Using Samatha
Using Samatha So I decided to try out David Springates Samatha package for statically building this blog. If you decide to use it, be warned, right now it is a...
Weekend Reading: F-Squared
Mebane Faber posted another interesting blog post: Building a Simple Sector Rotation on Momentum and Trend that caught my interest. Today I want to show how you can test...
CSI Stats: looking for traces of data fraud in R
Recently, I was looking at some published research, and I became concerned that it looked strange. Firstly, it had results wildly different to other similar studies, and more exciting...
Le Monde puzzle [#843]
A Le Monde mathematical puzzle of moderate difficulty: How many binary quintuplets (a,b,c,d,e) can be found such that any pair of quintuplets differs by at least two digits? I...
24 Days of R: Day 6
I've finally had some success at munging some HTML. For quite some time, I've wanted to render a county level choropleth for US presidential election results. The numbers are...
Writing Type-Stable Code in Julia
For many of the people I talk to, Julia’s main appeal is speed. But achieving peak performance in Julia requires that programmers absorb a few subtle concepts that are...
On the growth of R and Python for data science
A recent article by Matt Asay claims that "Python is displacing R as the language for data science". Python has certainly made some great strides in recent years, evolving...
Three Quick and Simple Data Cleaning Helper Functions (December 2013)
As I go about cleaning and merging data sets with R I often end up creating and using simple functions over and over. When this happens, I stick them...
R / Bioconductor for High-Throughput Sequence Analysis
I would like to recommend a recent workshop material on R/Bioconductor from Marc Carlson et al.http://www.bioconductor.org/help/course-materials/2013/SeattleMay2013/PDF: IntermediateSequenceAnalysis2013.pdfR script: IntermediateSequenceAnalysis201...
New package: jsonlite. A smart(er) JSON encoder/decoder.
This week we released a new package on CRAN: jsonlite. This package is a fork of RJSONIO by Duncan Temple Lang...
Incidental Parameters Problem with Binary Response Data and Unobserved Individual Effects
It is a well known problem that in some models as the number of observations becomes large, econometric estimators fail to converge on consistent estimators. The leading case of...
24 Days of R: Day 5
Some time back, I started a project on GitHub wherein I would explore the efficacy of financial literacy efforts in the area where I live. This is done with...
Conditional densities, on one single graph
With Stéphane Tufféry we’ve been working on credit scoring1 and we’ve been using the popular german credit dataset, > myVariableNames <- c("checking_status","duration","credit_history", + "purpose","credit_amount","savings","employment","installment_rate", + "personal_status","other_parties","residence_since","property_magnitude", + "age","other_payment_plans","housing","existing_credits","job", +...
Check if a Variable Exists in R
If you use attach, it is easy to tell if a variable exists. You can simply use exists to check:>attach(df)>exists("varName") TRUEHowever, if you don't use attach (and I find you generally...
A conversation with Robert Scoble
I had the pleasure of visiting technology guru Robert Scoble at Rackspace Labs a few weeks ago. We had a great conversation about the Big Data revolution, and how...
