February 2011

Child health metrics

February 20, 2011 | nzcoops

In analysis of Child Health data, generally z-scores or percentile groupings are used as children do not growth is not linear. The CDC (Center for Disease Control and Prevention) have released tables of data for calculating these z-scores and percentiles, and here are some scripts for R to calculate these ... [Read more...]

R versus Matlab in Mathematical Psychology

February 20, 2011 | Jeromy Anglim

I recently attended the 2011 Australasian Mathematical Psychology Conference.This post summarises a few thoughts I had on the use of R, Matlab and othertools in mathematical psychology flowing from discussions with researchers atthe conference.I wanted...
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Converting MATLAB and R date and time values

February 20, 2011 | Luke Miller

For some unknown reason, MATLAB codes its date/time values as the number of elapsed days starting from January 1 in the year 0000. R uses the equally arbitrary, but much more widespread POSIX/Unix epoch as a reference for time keeping, so that R’... [Read more...]

Vectorize!

February 20, 2011 | xi'an

Here is an email sent by one of my students a few days ago: Do you know how to integrate a function with an  “if”? For instance: __X=rnorm(100) __Femp=function(x){ +   return(sum(Xintegrate(Femp,0,1)$value does not work. My reply was that the fundamental reason it does not ... [Read more...]

Dataset: Tweets from the Chinese Protests #cn220

February 20, 2011 | mjbommar

  Earlier this week, I posted a ~100k tweet dataset on the #25bahman protests in Iran.  The corresponding figure of frequencies showed a strong presence on Twitter, with over 500 tweets per 5 minute period at peak.  You can download the … Continue reading → [Read more...]

New R features in Bio7 1.5

February 20, 2011 | » R

Bio7 1.5 has been released and comes with new functionalities for R. For all who don’t know Bio7 here is a short description: Bio7 is a integrated development environment for ecological modelling based on the Rich-Client-Platform concept of the Java IDE Eclipse. The Bio7 platform contains several perspectives which arrange ... [Read more...]

UseR! 2011 in Warwick

February 20, 2011 | xi'an

This year useR! conference will take place in Warwick, on August 16-18.  It is being organised by the department of Statistics and funded by CRiSM and Revolution Analytics (providers of the R tee-shirt!). I wish I could attend but mid-August is usually associated with genuine (post-JSM) family vacations. Filed under: ... [Read more...]

Software tools for data analysis – an overview

February 19, 2011 | Szilard

by Szilard Pafka Discussions on various software tools (C, C++, Perl, Python, Unix shell, R, Matlab, SAS, SPSS, Excel, databases, Hadoop etc.) used in data analysis. Szilard Pafka (founder and co-organizer of the Los Angeles R users group) presents an … Continue reading →
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Parallel computation [permutations]

February 19, 2011 | xi'an

François Perron is visiting me for two months from Montréal and, following a discussion about the parallel implementation of MCMC algorithms—to which he also contributed with Yves Atchadé in 2005—, he remarked that a deterministic choice of permutations with the maximal contrast should do better than random or ... [Read more...]

Screen Scraping, Mapping in R

February 19, 2011 | Earl Glynn

by Earl F. Glynn, Kansas Watchdog The PowerPoint slides below give an overview of screen scraping and mapping in R. Details with comments about many of the R statements can be found in these articles: Simple R Screen Scraping Example R Screen Scraping:... [Read more...]

R Bloggers: The Site I Wish Existed in 2007

February 19, 2011 | mjbommar

  My first experience with R was in 2007 as a sophomore in undergrad.  As part of a larger project on pricing day-ahead electricity futures, I wanted to cluster locational marginal price (LMP) data from the ISO-NE.  Something like k-means is easy … Continue reading → [Read more...]

IBM has a Natural Language Purpose

February 19, 2011 | Larry D'Agostino

I wanted to write a blog post about the advancements of Natural Language Processing in light of the performance of IBM's Watson on the Jeopardy challenge last week.  Natural Language Processing is the science of transforming and interpreting human... [Read more...]

RcppArmadillo 0.2.13

February 19, 2011 | Thinking inside the box

Yesterday Conrad Sanderson released version 1.1.4 of his Armadillo templated C++ library for linear algebra, so hot on the heels our 0.2.12 release from a few days ago comes version 0.2.13 of RcppArmadillo, our Rcpp-based integration into R. This new... [Read more...]
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