Hello. I have a data base with 50 qualitative variables and a lot of individuals. I try to estimate the links between one of these variables (landcover) and the 49 others (geomorphology, hydrography...). I want to use a "discriminant analysis on qualitative variables" (as DISQUAL in SPAD) or a " log-linear model ". Which R-Package(s) or other methods can you advise me. Thank you for you help. POMazagol Centre de Recherches sur l'ENvironnement et l'AM??nagement UMR 5600 Cnrs "Ville-Environnement-Soci??t??" 6 Rue Basse des Rives 42023 - Saint Etienne cedex 02 Tel : +33(0)4 77 42 19 23 Fax : +33(0)4 77 42 19 24 http://www.univ-st-etienne.fr/crenam/vielabo/chercheur/mazagol/ Bonjour. Je dispose d'une base de donn??es paysag??re constitu??e exclusivement 50 variables qualitatives nominales et d'un grand nombre d'individus. Je cherche ?? estimer les liens existant entre une de ces variables (occupation du sol) et les 50 autres (variables g??omorphologiques, hydrographiques...). J'ai enviseag?? d'utiliser une "analyse discriminante sur variables qualitatives" (??quivalent ?? DISQUAL dans SPAD) ou alors un "mod??le log-lin??aire". Je souhaiterais connaitre quels packages R vous paraissent les plus judicieux pour mener ?? bien ces m??thodes. A moins que vous ne me conseilliez une autre m??thode. Merci d'avance. POMazagol
I don't think this is `discriminant analysis' as used in English (the French translation has a wider meaning). I suggest you start with multinom (in package nnet, part of the standard R distribution) which does fit a log-linear model, and rpart (in package rpart) as a classification tree is often useful to select variables in this sort of problem (and with 49 explanatory variables you are presumably hoping that only a few are needed). On Fri, 23 Jul 2004, Pierre.Olivier.Mazagol wrote:> Hello. > I have a data base with 50 qualitative variables and a lot of > individuals. I try to estimate the links between one of these variables > (landcover) and the 49 others (geomorphology, hydrography...). I want to > use a "discriminant analysis on qualitative variables" (as DISQUAL in > SPAD) or a " log-linear model ". Which R-Package(s) or other methods can > you advise me.-- Brian D. Ripley, ripley at stats.ox.ac.uk Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/ University of Oxford, Tel: +44 1865 272861 (self) 1 South Parks Road, +44 1865 272866 (PA) Oxford OX1 3TG, UK Fax: +44 1865 272595