Here is an amazing set of photographs of C.C. Li, who was the founder of the Division of Human Genetics within the Department of Biostatistics at the University of Pittsburgh.  

Markov Chain Humor

Possible mascots for a program that uses Markov Chains in its computations:

Markov Man
   "Look, it's a bird... no, it's a plane,... no, I forgot what it was."


Hidden Markov Man
   the truly Forgetful Man

Computers are useful?!

"A computer makes it possible to do, in half an hour, tasks which were completely unnecessary to do before" ~ Dave Barry.

Zero p-values in R

For the top hits from an R program, I was getting all zero p-values, which are not that useful for ranking or plotting.

Turns out that the R program was calculating the p-value in this manner:

1 - pchisq(71.12830,1)

But, according to the discussion here, in R

".Machine$double.eps is the smallest number such that 1+x can be distinguished from 1"

On my machine, we have that:

> .Machine$double.eps
[1] 2.220446e-16

So that is why this truncates to zero:

> 1 - pchisq(71.12830,1)
[1] 0

However, we can get a non-zero p-value if instead we compute it this way:

> pchisq(71.12830,1,lower.tail=FALSE)
[1] 3.347341e-17

knitr

I recently became aware of the kintr package http://yihui.name/knitr/ which is much more capable and easier to use than Sweave when creating dynamic 'reproducible research' reports that interweave LaTeX and R.

Quertle http://www.quertle.info/

I learned today about an amazing new program for searching the PubMed literature database plus full text documents - this is called 'Quertle'  http://www.quertle.info/ 

I tried it out and quickly found an important and relevant paper that we hadn't found in an earlier more extensive conventional literature search.

Your genetic profile

Craig Venter said, in response to a question about the 'risks' of knowing one's genetic makeup:

"Understanding the genetic code is understanding probabilities.  There is very little in your code that is yes/no."