The next major release of R has been announced: R 2.14.0 is scheduled for October 31. Details are still coming in about the new features planned for this release, but R core member Luke Tierney has revealed some of the performance improvements expected, and R core member Brian Ripley has spoken of forthcoming low-level support for multi-threaded computing and...
Monthly Archives: September 2011
Appendable saving in R
One of the most crucial problems in HPC is that every error you make have much greater impact than in the normal computing — there is nothing more amusing than finding out that few-day simulation broke few minutes before the end because of an unfortunate value thrown by a random generator, typo in result saving code or
Three free books for better programming in R (and any other language)
Like many users and producers of R packages, I have never had any formal training in computer science. I’ve come to to the conclusion that this is a serious omission in a professional researcher’s training. Computer scientists and professional hackers … Continue reading →
rgdal + raster + RCurl = My next package
This package has been a long time in the making. In the end it’s more of a data package than a functional package, but pulling all the pieces together required me to learn some really cool packages: raster ( which I already knew ) rgdal and RCurl. I’ll provide a littel bit of an overview 
DTW: dynamic time warping 动态时间规整
Basically, DTW (dynamic time warping) is an algorithm to output cumulative distance of two time sequences, which is widely used e.g. for classification and clustering.
For example, when using k-mean for clustering, we can use DTW as distance function. Here is one of such nice instances (using R: http://www.rdatamining.com/examples/ts-mining)
Relevant information from Anshul's email.
For example, when using k-mean for clustering, we can use DTW as distance function. Here is one of such nice instances (using R: http://www.rdatamining.com/examples/ts-mining)
Relevant information from Anshul's email.
A review of DTW http://csdl.ics.hawaii.edu/techreports/08-04/08-04.pdfCode:Python code: https://mlpy.fbk.eu/R...
Map the distribution of your sample by geolocating ip addresses or zip codes
Yesterday I wanted to create a map of participants from a study on social media and partisan selective exposure that Sean Westwood and I ran recently, with participants from Amazon’s Mechanical Turk. We recorded ip addresses for each Turker participant, so … Continue reading →
Implementation of the CDC Growth Charts in R
I implemented in R a function to re-create the CDC Growth Chart, according to the data provided by the CDC.In order to use this function, you need to download the .rar file available at this megaupload link.Mirror: mediafire link.Then unrar the file, a...
Bayesian Models with Censored Data: A comparison of OLS, tobit and bayesian models
The following R code models a censored dependent variable (in this case academic aptitude) using a traditional least squares, tobit, and Bayesian approaches. As depicted below, the OLS estimates (blue) for censored data are inconsistent and will ...
The Long Tail of the Pareto Distribution
In my last two posts, I have discussed cases where the mean is of little or no use as a data characterization. One of the specific examples I discussed last time was the case of the Pareto type I distribution, for which the density is given by:
p(x) = aka/xa+1
defined for all x > k, where k and a...
littler 0.1.5
Brown-bag release time for littler. One of the minor cleanups in the 0.1.4 release from Thursday actually introduced a nasty little bug as you can't call Rf_KillAllDevices() when you do not have any graphics device. Doh. So with apologies for the l...
Zero Inflated Models and Generalized Linear Mixed Models with R.
Zuur, Saveliev, Ieno (2012).
