Hi, x1 <- c(as.Date("20110101","%Y%m%d"),as.Date("2012-01-01","%Y-%m-%d")); x2 <- c("1","2");
ddf <- data.frame(x=x1,y=x2); ddf[["y"]] <- as.factor(ddf[["y"]]) write.arff(ddf, file="D:/ddf.arff") Content of ddf.arff is @relation ddf @attribute x numeric @attribute y {'1','2'} @data 2011-01-01,'1' 2012-01-01,'2' Here x is of type Date, but write.arff write it as numeric, but the actual content is string, the result file is not with valid ARFF file format(Weka can't read it in). I think write.arff should write it as @attribute x DATE "yyyy-MM-dd" Regards Xiaobo Gu [[alternative HTML version deleted]] ______________________________________________ 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.