-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Hi
My brain is giving up on this... I have the following two data.frames: x <- data.frame(ref=c(NA, NA, NA, 10:5, NA, 1:5)) y <- data.frame(id = c(2, 3, 4, 6, 7, 9, 8), val = 101:107) Which look as follow: > x ref 1 NA 2 NA 3 NA 4 10 5 9 6 8 7 7 8 6 9 5 10 NA 11 1 12 2 13 3 14 4 15 5 > y id val 1 2 101 2 3 102 3 4 103 4 6 104 5 7 105 6 9 106 7 8 107 > Now I want to merge y into x, but that a) the sort order of x stays the same (sort=FALSE in merge()) and b) the NAs stay The result should look as follow (column id only here for clarity): > result ref id val 1 NA NA NA 2 NA NA NA 3 NA NA NA 4 10 NA NA 5 9 9 106 6 8 8 107 7 7 7 105 8 6 6 104 9 5 NA NA 10 NA NA NA 11 1 NA NA 12 2 2 101 13 3 3 102 14 4 4 103 15 5 NA NA merge(x, y, by.x="ref", by.y="id", sort=FALSE) leaves out the NA, but otherwise it works: > merge(x, y, by.x=1, by.y="id", sort=FALSE) ref val 1 9 106 2 8 107 3 7 105 4 6 104 5 2 101 6 3 102 7 4 103 Is there any way that I can tell merge() to keep the NA, or how can I achieve what I want? Thanks, Rainer - -- Rainer M. Krug, PhD (Conservation Ecology, SUN), MSc (Conservation Biology, UCT), Dipl. Phys. (Germany) Centre of Excellence for Invasion Biology Stellenbosch University South Africa Tel : +33 - (0)9 53 10 27 44 Cell: +33 - (0)6 85 62 59 98 Fax : +33 - (0)9 58 10 27 44 Fax (D): +49 - (0)3 21 21 25 22 44 email: rai...@krugs.de Skype: RMkrug -----BEGIN PGP SIGNATURE----- Version: GnuPG/MacGPG2 v2.0.22 (Darwin) Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/ iQEcBAEBAgAGBQJSoJQpAAoJENvXNx4PUvmCW2oH/A9s2HbZ16PZRmFcQsxH3uYC T20b1HXQu8iVqVkfD1D1tbPnogU5QJF1+tJMVzwkg+enhDtop6qpS5Vm5RV9KFnk eJxmwdIQI3sZOkpReH9cPCnG0bHGO5f+iW3fA7mx95jQTm8WHaU+7zo7Ueb62oeX /Toc4cVKI2qljzRfJkJCyKZclXbTe0YRv/EKqHDjyI1k/1/1jYVxALm/CqvSZTQQ SE7nhDVvKHbuBfvrH4A5iy0X/TyHTYgP5eVV7/W4D4OcBYgQDJMwm1z0JTKeF37Z e1gaUEkDbbJrNIOvB5Bl9EWaym0FFyv7w9XUV/FtqJy7QgQ6qoNxUAo1CfXkx/s= =hX0S -----END PGP SIGNATURE----- ______________________________________________ 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.