hi, I have a question about merging two files. For example, I have two files, the first file is like the following:
id trait1 1 10.2 2 11.1 3 9.7 6 10.2 7 8.9 10 9.7 11 10.2 The second file is like the following: id trait2 1 9.8 2 10.8 4 7.8 5 9.8 6 10.1 12 10.2 13 10.1 now I want to merge the two files by the variable "id", I only want to keep the "id"s which show up in the first file. Even the "id" does not show up in the second file, it doesn't matter, I can keep the missing values. So my question is: how can I merge the two files and keep only the rows whose "id" show up in the first file? I know how to do it is SAS, just use the following code: merge data1(in=in1) data2(in=in2); by id; if in1; but I really have no idea about how to do it in R. thank you in advance, karean -- View this message in context: http://n4.nabble.com/merging-issue-tp1013356p1013356.html Sent from the R help mailing list archive at Nabble.com. ______________________________________________ [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 and provide commented, minimal, self-contained, reproducible code.
