Dear Michael:
I have not yet put this in a computer program but you may wish to look at the
method I used in Chapter 6 of Information Theory and Molecular Biology
Cambridge University Press 1992. ISBN 0 521 35005 0
See especially Figures 6.1 through 6.4 for a stereograph representation of the
relation of amino acids to each other in evolution.
Best regards Hubert P. Yockey hpyockey at aol.com