In Chapter 6 (correlation and covariance) I consider how to construct a confidence interval (CI) for the difference between two independent correlations. The standard approach uses the Fisher z transformation to deal with boundary effects (the squashing of the distribution and increasing asymmetry as r approaches -1 or 1). As zr is approximately normally distributed 
December and January were crazy months, with a lot of travel and suddenly I found myself in February working in four parallel projects involving quantitative genetics data analyses. (I’ll write about some of them very soon) Anyhow, as I have … Continue reading →
After playing around with R studio server for a while, I decided to write a followup to my previous blog post. I want to go over a few of the strong points of using RStudio server to access a remote… See more ›
Running 64 bit R, JAGS and rjags on EC2 Winbugs and Jags free Item Response Theory from the dot matrix plots of proprietary software and open up a multicoloured world of posterior predictive model checking. Fitting IRT models using brute force is not ...
Yesterday, Haydn Shaughnnessy wrote a piece for Forbes titled, Who are the Top 20 Influencers in Big Data?
Fans of R will be delighted to see David Smith of Revolution Analytics up there at number 2!
Congratulations!
This is the second post in the series about Multiple Factor Models. I will build on the code presented in the prior post, Multiple Factor Model – Fundamental Data, and I will show how to build Fundamental factors described in the CSFB Alpha Factor Framework. For details of the CSFB Alpha Factor Framework please read 
This week I reimplemented part of Conic Sections 1 model from NetLogo. In the model turtles seek to to be in target distance from center.My code takes only one center point, so only circles can be obtained. Apart from turtle location plot giv...
Few years ago, a newspaper claimed the block I live in — Prenzlauer Berg in Berlin — is the most fertile region in Europe. It was a hoax, as this (German) newspaper article points out. (The article has become quite famous because it coined the term Bionade Biedermeier to describe the life style in this area.)
However,...
If you live in Paris and are interested in R, there will be two meetings for you this week. First a Semin-R session, organized at the Muséum National d’Histoire Naturelle on Tuesday 7 Feb (too bad, the Museum is closed on Tuesdays). Presentations will be about colors, phylogenies and maps, while I will speak about 
Zero Inflated Models and Generalized Linear Mixed Models with R.
Zuur, Saveliev, Ieno (2012).
