Nell’ambito delle attività del gruppo di ricerca del Dipartimento di Statistica COFIN2004 "Apprendimento in modelli grafici e inferenza causale con applicazioni in ambito economico-sociale, genetico e forense", il prof. Claus Dethlefsen del Department of Mathematical Sciences, Aalborg University, Denmark e il prof. Jens Henrik Badsberg, del Department of Animal Breeding and Genetics, Danish Institute of Agricultural Sciences, Denmark, terranno i seguenti seminari:

Deal and gRbase

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CoCo in R

I seminari si terranno martedì 30 marzo 2004, alle ore 9.30, presso l’aula 32 del Dipartimento.

Tutti gli interessati sono invitati a partecipare.

Un breve abstract dei due seminari è riportato nel seguito.

Deal and gRbase

A module for R, gRbase, is being developed. The goal is to create common grounds for implementation of graphical model software in R. We have tried to define basic structures that are extensible to encompass at least existing models and methodology. The current version of gRbase is a minimal version, implementing only loglinear models. Deal is an R package for learning Bayesiannetworks with both continuous and discrete variables. We show how deal can make use of the graphical interface provided by the package dynamicGraph.

References:

http://www.jstatsoft.org/v08/i20/

http://lib.stat.cmu.edu/R/CRAN/src/contrib/PACKAGES.html#deal

CoCo in R

CoCo for graphical models with discrete variables has been around for some time.

Some of the features of CoCo are efficient algorithms for large contingency tables, exact tests, the EM algorithm, and procedures for model selection.  The program has been extended to also handle continuous variables, by Gaussian graphical models and CG distributions. CoCo can now be used from R under Windows as well as Linux. Lately a tool for interacting with the graphs of the models has been implemented in R. This tool, dynamicGraph, can also be used for other packages.

References:

Steffen L. Lauritzen (1996). Graphical Models. Oxford.

http://www.jbs.agrsci.dk/Biometry/Software-Datasets/CoCo/CoCo.1.6/

http://lib.stat.cmu.edu/R/CRAN/src/contrib/PACKAGES.html#dynamicGrap

http://www.jstatsoft.org/v06/i04/guide-JSS-1.pdf