I briefly mentioned "time" in the previously posted Linux command line cheat sheet, but I can't overstate its utility especially for ACCRE/Vampire users. The time command does exactly what it sounds like: it times exactly how long it takes to run anything at the command line. And it couldn't be easier to use.

What's your power to detect a recessive effect with an odds ratio of 1.2 for a disease with 4.2% prevalence using 1200 cases and 2900 controls? What if the allele is rare? Is it worth it, in terms of power gain, to genotype 1000 more individuals? How small of an effect can you detect with 80% power using the data you have? These questions and others can be answered by power and sample size calculations.

If you're interested in gene-gene and gene-environment interaction (and who wouldn't be?), then you should check out the Epistasis Blog. Our friend and colleague Jason Moore at Dartmouth Medical School has maintained compgen.blogspot.com since 2005 writing about epistasis, computational genetics, and related topics.

Will recently posted a set of flowcharts made by Marylyn, Jason, and Tricia, to help choose which statistical analysis to use for nearly any situation. UCLA has a very similar chart with links to Stata code, examples, and annotated output for every method they mention. Also, check out their Stata help homepage and Stata learning modules.

This abstract in BMC Bioinformatics was presented in our Computational Genetics Journal Club a few weeks back: "Gene Prospector: An evidence gateway for evaluating potential susceptibility genes and interacting risk factors for human diseases."As described by the authors at CDC, Gene Prospector is a bioinformatics tool designed to sort, rank, and display information about genes in relation to human diseases, risk factors and other

For the second installment in our Noteworthy Blog series, take a look at Chun Li's biostatistics course blog. Several years ago, CHGR faculty member Chun Li taught a class in biostatistics, maintaining this blog over the duration of the course.

How often have you needed to extract a certain column from a file, or strip out only a few individuals from a ped file? This is often done with Excel, but that requires loading the data, manipulating it, then saving it back into a format that is acceptable, which may require converting tabs to spaces or other aggravating things.

And it will do way more than display "Hello, world!" to the screen. An anonymous commenter on one of our Linux posts recently asked how to write scripts that will automate the same analysis on multiple files. While there are potentially several ways to do this, perl will almost always get the job done.

`screen` is one of the most useful system tools I've ever used. It allows you to begin a process and then detach from the process to let it continue to run in the background.

For those of you who attend our computational genetics journal club every other week, you've all heard about this. Say what you will about the "consumer genetics" enterprise, 23andMe maintains an excellent blog. In their "SNPwatch" category, The Spittoon surveys and summarizes the latest findings in human genetics research before they hit the press.

If you've ever had trouble getting started doing a data analysis, you are certainly not alone. Should I run an ANOVA, MANOVA, ANCOVA, or MANCOVA? Should that have been a McNemar's test, a Kruskal-Wallis, or a Mann-Whitney U?To at least pin down the statistical test you should run, consult these excellent flowcharts by Marylyn Ritchie, Jason Moore, and Tricia Thornton-Wells.