-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On 12/05/13, 16:11 , Sarah Goslee wrote: > Adding the argument all.x=TRUE to merge() will retain the NA > values, but the only reliable way I've found to preserve order with > NA values in a merge is to add an index column to x, merge the > data, sort on the index column, then delete it.
Thanks Sarah - that works nicely, although it is a not so nice workaround 0 there should be an argument in merge to keep NA... Cheers, Rainer > > Sarah > > On Thu, Dec 5, 2013 at 9:56 AM, Rainer M Krug <rai...@krugs.de> > wrote: >> -----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/ iQEcBAEBAgAGBQJSoYwnAAoJENvXNx4PUvmCTjwH/2s8NdixLDI7uWvZ0p90wFxK OMq9IcOTQ/VEK6ksYzN5e8Q6ukGCgMPW2OKqrLkqr9xhtt49toWR64CgXGgqnKYu Vu5BT8MldwvtLYLWjyGGlrsz4VXFBixTQxfPPltSXakT742Wno7T0OLIL7V8FBgk AqdRZpN6+QfBiQGFO7doXWndvnvXXD3uOqEAe89xwV3PBNHLCNDcMKY74HQ+t4F+ RrBzKZRvBOrwyfHFGFGfvEluewpcsPY2ooR/TqcO1XaLz94A5F2RcHdedqkIcdln tEcOWZq9j9RWQo/9Af4pdxv9CClt8molP3rG4JRYA4x9JiSj4GNYNNF5wnofTAw= =nxjF -----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.
