[BioPython] equation

[Ernesto]

Hi all,
I would normalize a DNA substitution matrix to have the sum of off diagonal entries equal 1.
How can I estimate parameters to this scope in Python?

For example in the most complicated case I should solve the following equation:

2a(Fac)+2b(Fag)+2c(Fcg)+2d(Fta)+2e(Fct)+2f(Fgt) = 1

where Fac Fag Fcg Fta Fct Fgt are known.

I would detect a b c d e.

Thanks a lot

Ernesto