A tutorial on using the biomaRt R package to retrieve data from online databases like Ensembl.
Simply follow along in biomaRt_demo.R and you will learn how to use the biomaRt package.
The GTF_converter.R script is an example of how to use biomaRt to do real work (converting gene ids in this case). The demo .gtf was created using the getGTF.sh shell script.
This tutorial is also available as a webcast.
To install the required packages for this tutorial, enter the following commands in the R console:
install.packages("stringr")
source("http://bioconductor.org/biocLite.R")
biocLite("biomaRt")