Re: [Gaul-devel] Tutorial updates.

[Stewart A. <ad...@mc...>]

Hi,

Asier wrote:
> I must work with "mixed" individuals: some genes in a chromosome are co=
ded
> as discrete values (integers) and others as continuous values. I think =
it
> can't be done with GAUL right now.=20

Using mixed chromosome types is relatively straight forward in GAUL, but=20
it does require a custom chromosome type to be created.  There are also=20
a couple of approaches to this, but the best (simplist) is to make use=20
of the support for multiple chromosomes.  I shall send you some code to=20
demonstrate this, later.

> Perhaps defining custom operators and constructors but crossover... I
> think is the more problematic one. =BFAny ideas?

Just treat the integer parts seperately from the continuous parts.=20
Perform, say, douple-point crossover on the 'int's and then, say,=20
douple-point crossover on the 'double's.  If the Nth int is dependent=20
upon the Nth double, or visa versa, perform the crossovers at the same=20
point(s).  Otherwise, crossover at randomly selected points for each.

> I've developed a library (now in "beta" state) with a lot of ideas from
> GAUL and libga100 but it's oriented to EDAs (Estimation of Distribution
> Algorithms, http://scsx01.sc.ehu.es/ccwbayes/EDA/EDAOverviewinaki.html)=
 and
> I have solved it with a new "type" I have called "mixed", but it's easy=
 to
> implement because in this algorithms the work is by "columns" of data.

This is really cool.  Coincidently, I was advising collegue of mine on a=20
very similar topic yesterday.  In addition, I was just about to start=20
implementing a similar looking algorithm (as discussed in Glick, Rayan,=20
and Goldbulm, (2002) Proceedings of the National Academy of Sciences 99:=20
703-708).  Please keep me up-to-date on your EDA library!

Regards,
Stewart.

--=20
________________________________________________________________________
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     Stewart Adcock, Department of Chemistry and Biochemistry, UCSD,
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