Hi.
Your best bet is to take the log of the marginal likelihood so you are
dealing with smaller numbers, and use the gamma function instead of
factorials. See Heckerman's tutorial
(http://research.microsoft.com/~heckerman/) for the gamma-function version
of the Marginal likelihood. A constant-time series solution can be used to
calculate the log-gamma functions, see Numerical Recipes for details:
http://www.ulib.org/webRoot/Books/Numerical_Recipes/bookcpdf/c6-1.pdf
Best,
Denver.
-----
Denver Dash http://www.sis.pitt.edu/~ddash
----- Original Message -----
From: "Estevam Rafael Hruschka Junior" <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: Monday, May 21, 2001 6:33 PM
Subject: [UAI] K2 learning
> Hi all,
>
> I'm using the K2 algorithm (Cooper & Herskovitz, 1992) to learn a bayesian
> model from data. The point is that in this algorithm I need to compute the
> fatorial of Nijk (the number of cases in which a variable xi has the value
> vik, and the parent of x is instantiated as wij). When the number of cases
> (in the database) is big, I can't compute this fatorial.
> I was wondering if anybody have already faced this problem and have any
> sugestion.
>
> Thank you in advance,
>
> Estevam.
>
> - -_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_
> Estevam Rafael Hruschka Junior
> Curitiba - PR - Brazil
> e-mail: [EMAIL PROTECTED]
>
>
