Dear R-listers, I have to explain "y", a continous variable, with two variables "t" and "p" which are "factor variables": t is [1:12] and p is [1:18] (a value for y for each combination t*p). OK, then I try to adjust models like: y=a_p + b*t (I mean as many intercepts as levels of p) or y=a_p + b_p*t (as many intercepts and coefficients for t as levels of p). How is it possible to do that with GLM? other package? Thank you for advance, best regards, EASauleau. ===========================================Erik-Andr? SAULEAU SEAIM H?pital du Hasenrain BP 1070 87, Avenue de Altkirch 68051 MULHOUSE C?dex Tel: 03-89-64-79-95 M?l: sauleauea at ch-mulhouse.fr =========================================== ************************************************************************************ Afin d'?viter toute propagation de virus informatique, et en compl?ment des dispositifs en place, ce message (et ses pi?ces jointes s'il y en a) a ?t? automatiquement analys? par un antivirus de messagerie. *********************************************************************************** -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.- r-help mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html Send "info", "help", or "[un]subscribe" (in the "body", not the subject !) To: r-help-request at stat.math.ethz.ch _._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._