Hi everybody, I got a solution for my problem with Eric Paniagua (many thanks!)! Thank you a lot everybody!
Paniagua said explained that I was losing row.names when I merged a data.frame with a factor object (data2$color), because a factor objects don't have row.names. Instead of merging data1 to data2$color, I merged it to data2["color"] (still a data.frame objcet). It preserves row.names. When I do: d1 <- merge(data1, data2["color"], by=0, all.x=T) It creates a new variable on column 1, with the original row.names, so I have to transform this data.frame in a new one, using this variable as the row.names: d2 <- data.frame(d1, row.names=1) It does the job, but row.names are not in the same order as in data1, so I reorder it: d2[row.names(data1),] And it gives me the dataframe data1, binded to the new variable color, with the NAs in the proper position. Thank you all! Cheers, Joao D. -- View this message in context: http://r.789695.n4.nabble.com/Merge-dataframes-tp3882222p3885316.html Sent from the R help mailing list archive at Nabble.com. ______________________________________________ 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.
