Hi, this is a simple question
I have this data.frame: > test <- data.frame(var1=c(1,1,1,1,1,1),var2=c("a","a","b","c","d","e"),var3=c("a1","a1","b1","a1","c1","d1")) > test var1 var2 var3 1 1 a a1 2 1 a a1 3 1 b b1 4 1 c a1 5 1 d c1 6 1 e d1 Then I need to calculate the number of var3 excluding the repeated measure of var2. With tapply I have this: > tapply(test$var1,test$var3,sum) a1 b1 c1 d1 3 1 1 1 But the correct result is: a1 b1 c1 d1 2 1 1 1 because on factor "a1" in var3 I have 2 repeated factor "a" in var2. I try a simple solution for it but without success. aggregate function dont work with factors (var3 by var1). Anybody have an idea? Thanks Ronaldo -- "It's men like him that give the Y chromosome a bad name." -- > Prof. Ronaldo Reis Júnior | .''`. UNIMONTES/DBG/Lab. Ecologia Comportamental e Computacional | : :' : Campus Universitário Prof. Darcy Ribeiro, Vila Mauricéia | `. `'` CP: 126, CEP: 39401-089, Montes Claros - MG - Brasil | `- Fone: (38) 3229-8192 | ronaldo.r...@unimontes.br | chrys...@gmail.com | http://www.ppgcb.unimontes.br/lecc | ICQ#: 5692561 | LinuxUser#: 205366 -- Favor NÃO ENVIAR arquivos do Word ou Powerpoint Prefira enviar em PDF, Texto, OpenOffice (ODF), HTML, or RTF. ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.