New year, new resolutions. This year, as a personal challenge, I decided to create a blog where I could share (and also receive) some tricks and tips about R programming language. The main motivation behind this blog is to learn how to use Knitr (http://yihui.name/knitr/). While I'm ... [Read more...]

Sean Murphy co-organizes Data Business DC, among many other things. Hadley Wickham, having just taught workshops in DC for RStudio, shared with the DC R Meetup his view on the future, or at least the near future of Data Analysis. … Continue reading → The post The (near) Future of Data Analysis – ... [Read more...]

The best way for me to achieve deep understanding of a theorem is not through lengthy proofs alone, but through practical application/implementation or as they said in the Marine Corps Pract-App. One of the many reasons I love R is the ease to write functions and test results. The 2008 ... [Read more...]

Last year, I spent a morning trying to return to first principles when modeling loss reserves. (Brief aside to non-actuaries: a loss reserve is the financial provision set aside to pay for claims which have either not yet settled, or have not yet been reported. If that doesn’t sound ... [Read more...]

Coursera's free Computing for Data Analysis course starts today. It's a four week long course, requiring about 3-5 hours/week. A bit about the course:In this course you will learn how to program in R and how to use R for effective data analysis. Y... [Read more...]

R code and data for book “R and Data Mining: Examples and Case Studies” are now available at http://www.rdatamining.com/books/rdm/code. An online PDF version of the book (the first 11  chapters only) can also be downloaded at http://www.rdatamining.com/docs. Below are its … Continue ... [Read more...]

I’ve made some revisions and simplifications to the code to compile NFL data. It’s now all out on Github for anyone to play with in advance of the Superbowl. In the meantime, here’s a lovely picture comparing every team’s offense- as measured by total offensive yards- ... [Read more...]

In the past I've used the terms "R library" and "R package" synonymously (e.g. this blog post and this paper), but a careful reader has called me out. Mark Sharp notes that there are differences between libraries and packages. Chapter one of the R Manual Writing R Extensions gives ... [Read more...]

Sean Murphy co-organizes Data Business DC, among many other things. Hadley Wickham, having just taught workshops in DC for RStudio, shared with the DC R Meetup his view on the future, or at least the near future of Data Analysis. Herein lies my notes for this talk, spiffed up into ... [Read more...]

It took me a while to figure out how to use the animation package on my Windows OS. In making an animated GIF, the problem seems to have been quite simple in the end (and I should have been more patient in reading the instructions!) - Following installation of the ... [Read more...]

I really like gists as a quick way to include more lengthly code snippets into my blog posts. However, I am not a git user as such, and so I was quite concerned when I noticed that all my gists on this blog had vanished after Christmas. I suppose this ... [Read more...]

A StackOverflow question asked how convert from arma::umat to arma::mat. The former is format used for find and other logical indexing. For the particular example at hand, a call to the conv_to converter provided the solution. We rewrite the answer he... [Read more...]

2013 promises to be a great year for all statistics aficionado as today is the first day of the International Year of Statistics. More than 1400 organizations from 108 countries — professional […] [Read more...]

Sitting in my synagogue this past Saturday, I started thinking about the authorship analysis that I did using function word counts from texts authored by Shakespeare, Austen, etc.  I started to wonder if I could do something similar with the … Continue reading → [Read more...]

In the example below, 552 rows are extracted from a data frame with 10 million rows using six different methods. Results show a significant disparity between the least and the most efficient methods in terms of CPU time. Similar to the finding in my previous post, the method with data.table package ... [Read more...]

This blog post makes available a set of indicators discussed in a forthcoming edition of Digital Icons. In brief, the script takes a text input and calculates polarisation and mobilisation indexes based on the number of pronouns featured.The hypothesised relationship between pronouns and polarisation is one discussed extensively by ... [Read more...]

This is another way to pre-treat aspectra set with the SNV math-treatment (Standard Normal Variate). You can see the other one in the post : "Standard Normal Variate (SNV)".In this post, I use the R function "sweep".library(ChemometricsWithR)#in a... [Read more...]

Perhaps you are trying to add your nice new object as data for an R package. But wait. It has [gasp] foreign letters in its dimnames, so ’R CMD check’ will certainly complain. What you need is something to turn R’s natural Unicode-processing goodness into a relic from the ... [Read more...]

The R functions head and tail return the first (last) n elements of the input vector. With Rcpp sugar, the functions head and tail work the same way as they do in R. Here we use std::sort from the STL and then tail to return the top n items (... [Read more...]

The STL contains a very general looping or sweeping construct in the for_each algorith. It can be used with function objects (such as the simple square function used here) but also with custom class which can be used to keep to keep state. #include &lt... [Read more...]