In the course of working through my MODIS  LST project and reviewing the steps that Imhoff and Zhang took as well has the data preparations other researchers have taken ( Neteler ) the issue of MODIS Quality control bits came up.  Every MODIS  HDF file comes with multiple SDS or multiple layers ... [Read more...]

This brief tutorial illustrates how to combine S4 object oriented capabilities with function closures in order to develop classes with built in methods. Thanks to Hadley Wickham for the great contribution of material and tutorials made available on the web and to Bill Venables and Stefano Iacus for their kind ... [Read more...]

Graphs can provide an excellent way to emphasize a point and to quickly and efficiently show important information. Sadly, poor graphs can be a good way to waste space in an article, take up time in a presentation, and waste a lot of ink all while providing little to no ... [Read more...]

As you probably know, I am one of the strongest proponents of the Shiny package for developing interactive web applications Amongst the latest news from RStudio is that what was planned to be commercial software will now be free and Open Source (AGPLv3 license) To celebrate this momentous announcement, I ... [Read more...]

As in previous years, let me warn unwary readers that the links to Amazon.com and Amazon.fr found on this blog are actually susceptible to earn me a monetary gain [from 4% to 7%] if a purchase is made in the 24 hours following the entry on Amazon through this link, thanks ... [Read more...]

Last month's release of Revolution R Enterprise 6.1 added the capability to fit decision and regresson trees on large data sets (using a new parallel external memory algorithm included in the RevoScaleR package). It also introduced the possibility of applying this and the other big-data statistical methods of RevoScaleR to data ... [Read more...]

I found the following post regarding the anomalous metal object observed in a Curiosity Rover photo to be fascinating - specifically, the clever ways that some programmers used for filtering the image for the object. The following answer on mathematica.stackexchange.com was especially illuminating for its use of a ... [Read more...]

Today I went to the RStudio site to post a feature request.  I noticed up in the top navigation a link called "Shiny".  I like things that are shiny.  It turns out Shiny is a new package the RStudio team has developed for easily making r... [Read more...]

I'm usually quite a big fan of the content syndicated on R-Bloggers (as this post is), but I came across a post yesterday that was as statistically misguided as it was provocative. In this post, entitled "The Surprisingly Weak Case for Global Warming," the author (Matt Asher) claims that the ... [Read more...]

R, which was largely predominant in the academic world, has started picking up a lot in businesses as well. At least that is what I am witnessing among my colleagues. Lot of people have started experimenting with R, choosing the path to enlightenment. ... [Read more...]

igraph is a library for "complex network research". While it integrates very well with R and provides a lot of convenient functions, huge graphs put a quick end to all the joy. The good news is: not all functions in igraph have bad performanc... [Read more...]

Here. Indeed, I’d much rather be a legend than a myth. I just want to clarify one thing. Walter Hickey writes: [Antony Unwin and Andrew Gelman] collaborated on this presentation where they take a hard look at what’s wrong with the recent trends of data visualization and infographics. ... [Read more...]

I had a bit of a play with Shiny over the weekend, using the Ergast Motor Racing Data API and the magical Shiny library for R, that makes building interactive, browser based applications around R a breeze. As this is just a quick heads-up/review post, I’ll largely limit ... [Read more...]

Oftentimes we find ourselves collaborating with others who might not use R or prefer to use Stata to clean and manage their data. Luckily, there is the foreign package that permits handling data of different types (SAS, SPSS, Stata, etc.) within the R... [Read more...]

I already talked about networks a few times in this blog. In particular, I had this approach to explain spatial segregation in a city or to solve the Guess Who? problem. However, one of the question is how to generate a good network. Indeed, I aim to study strategy to ... [Read more...]

In celebration of my achieving 10,000 “reputation” on Stack Overflow, I’m re-posting one of my questions from there that was (as I had expected) deleted after being live for about 5 hours. In that time, I never really got a satisfactory answer, so if anyone wants to offer one in the ... [Read more...]

Lattice plots are a great way of displaying multivariate data in R. Deepayan Sarkar, the author of lattice, has written a fantastic book about Multivariate Data Visualization with R [1]. However, I often have to refer back to the help pages to remind myself how to set and change the legend ... [Read more...]

The cube, 41063625 (3453), can be permuted to produce two other cubes: 56623104 (3843) and 66430125 (4053). In fact, 41063625 is the smallest cube which has exactly three permutations of its digits which are also cube.Find the smallest cube for which exactly five permutations of its digits are cube. Read More: 372 Words Totally [Read more...]

New York Times columnist Charles Blow needed a chart to accompany his op-ed piece Lincoln, Liberty and Two Americas (about one-party control in state legislatures). So he turned to resident graphic editor Kevin Quealy, who found the source data and used R to create the chart below: If you'd like ... [Read more...]

A nice, but not very well known, interface to R is TeXmacs. (I have to say that I am not totally objective, since I wrote the interface between R and TeXmacs…) Here’s a sample window: In the following few posts I’d like to explain how to use this ... [Read more...]