R index is developed in interpreting signal detection data for human perception. In sensory research it is used to interpret ranking data. The value one gets out of an R-index calculation is interpreted as a confusion between samples tested. It has bee...
MENTALLY MULTIPLY NUMBERS BY THEMSELVES Assume you know your multiplication tables up to 10x10. Here's how to compute the squares of numbers from 11 to 100.
I recently thought about ways to visualize medications and their co-occurences in a group of children. As long as you want to visualize up to 4 different medications you can simply use Venn diagrams. There is a very nice R-package to generate these kind of graphics for you (for a description see: Chen and Boutros, 2011). But
I've only just started looking at the homicide data made available by the Philadelphia Inquirer in my free time (which is hard to come by lately). I've been thinking about what sorts of statistics I could do, or what kinds of additional data sets I cou...
![ABC in Roma [R lab #2]](http://feeds.wordpress.com/1.0/comments/xianblog.wordpress.com/15060/)
Here are the R codes of the second R lab organised by Serena Arima in supplement of my lectures (now completed!). This morning I covered ABC model choice and the following example is the benchmark used in the course (and in the paper) about the impact of summary statistics. (Warning! It takes a while to 
Much of the data that the analyst uses exhibits extraordinary range. For example: incomes, company sizes, popularity of books and any “winner takes all process”; (see: Living in A Lognormal World). Tukey recommended the logarithm as an important “stabilizing transform” (a transform that brings data into a more usable form prior to generating exploratory statistics, Related posts:
This is the first post of a series that describes how to download and parse specific data sets into R. These kinds of scripts can be functionalized further, but I doubt that these will ever find their way into a formal package. They are intended to be helpful to those facing similar tasks, but as 
This time I´m going to use my own data to develop a model to predict some fatty acid in the solid fat (pork).Samples had been analyzed in a NIT (Near Infrared Transmittance) instrument. The range of the wavelengths is from 850 to 1048 nm (100 data poi...
This is yet another experiment to see how good is the approximation of binomial probability when we use Poisson and normal distributions for scenarios with large $n$, and $p$ close to zero or one.
Consider a problem where the random variable $X$ follows a binomial distribution with a known probability of success $p$, and number of trials $n$. If $n$...
Insurance pricing is backwards and primitive, harking back to an era before computers. One standard (and good) textbook on the topic is Non-Life Insurance Pricing with Generalized Linear Models by Esbjorn Ohlsson and Born Johansson. We have been doing some work in this area recently. Needing a robust internal training course...
Zero Inflated Models and Generalized Linear Mixed Models with R.
Zuur, Saveliev, Ieno (2012).
