[ssml] Re: pdb-l: entropy for matrix

[Kevin Karplus]

The entropy of a substitution matrix tells you how much it generalizes
away from the single sequence it starts with.

Read

@article{altschul91,
              author  =  "Stephen F. Altschul",
               title  =  "Amino acid substitution matrices from an information theoretic perspective",
               pages  =  "555--565",
             journal  =  jmb,
              volume  =  "219",
                year  =  "1991"
}

A quick google search found tables relating PAM values and
entropy:
	http://www.psc.edu/biomed/genedoc/gdpid.htm

http://www-bioeng.ucsd.edu/research/research_groups/compbio/workshop/Lab_3/matrix_entropy.htm