On Sunday 12 September 2004 14:12, Christoph Lehmann wrote: > Dear R-users, dear Ron > > I use pls from the pls.pcr package for classification. Since I need to > know which variables are most influential onto the classification > performance, what criteria shall I look at: > > a) B, the array of regression coefficients for a certain model (means a > certain number of latent variables) (and: squared or absolute values?)
The regression coefficients give the most direct information on which variables influence the classification, although you must be careful with the interpretation if the variables are correlated. So it is the absolute magitude that is important; why would you look at the squared values? > > OR > > b) the weight matrix RR (or R in the De Jong publication; in Ding & > Gentleman this is the P Matrix and called 'loadings')? (and again: > squared or absolute values?) > The object that is returned contains X and Y loadings (which are _not_ equal to te RR matrix, btw); these are mainly used for interpretation. The regression coefficients give information on your complete model; the loadings on individual components of the model. Ron > > > and what about glpls (glpls1a) ? > shall I look at the 'coefficients' (regression coefficients)? > > Thanks for clarification > > Christoph -- Ron Wehrens Institute for Molecules and Materials, Analytical Chemistry Radboud University Email: [EMAIL PROTECTED] Toernooiveld 1 http://www.science.ru.nl/cac 6525 ED Nijmegen Tel: +31 24 365 2053 The Netherlands Fax: +31 24 365 2653 ______________________________________________ [EMAIL PROTECTED] mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html