Curving Normality

The way R-Project handles data differs from some mainstream statistical programs, such as SPSS. It can handle an unlimited number of data sets, as long as the memory of your computer can handle it. Often, the results of statistical tests or estimation-procedures are stored inside ‘data-sets’ as well. In order to be able to serve different needs, several different types of data-storage are available.

This edition of the R-Sessions will introduce some of the types of data-storage and shows how these objects are managed by R-Project.

In this edition of the R-Sessions the most basic of the basics are introduced. Attention will be paid to basic calculations, still the basis of every refined statistical analysis. Furthermore, storing data and using stored data in functions is introduced.

A freshly installed version of R-Project can do some pretty nice things already, but much more functionality can be obtained by installing packages that contain new functions. These packages are available by the internet and can be installed from within R-Project. Let’s say we want to use the lme4-package, which can be used to estimate linear and generalized multilevel models. The lme4-package does not come pre-installed with R-Project, so we have to download and install is manually. The way this is done is shown based on an R-installation on windows XP.

There are many good reasons to start using R. Obviously, there are some reasons not to use R, as well. Some of these reasons are shortly described here. In the end, it is just some kind of personal preference that leads a researcher to use one statistical package, or another. Here are some arguments as a base for your own evaluation.

R is a software package that is used for statistical analyses. It has a syntax-driven interface which allows for a high level of control, many add-on packages, an active community supporting the program and it’s users and an open structure. All in all, it aims to be statistical software that goes beyond pre-set analyses. Oh, and it is free too.

Those of you who have ever attended a ‘Fête Nos’, a typical Brêton festival-type of gathering with music and people dancing, may immediately understand what I’m going to write about. All the others who have attended another gathering of a …

I must admit that I repeatedly feel flattered by the number of page-views on my blog as shown by the WordPress statistics plugin. However, despite the nice graphical representation, they are a little too flattering for the humble number of …

Recently, I discussed the M.A.R.S simulation models developed by Iannaccone and Makowsky. Based on what I read, I decided to try to work out a similar simulation myself. I did so using R-Project and it resulted in the simulation shown …