If you look at the structure, you'll see: > x$V4 <- 0 > str(x) `data.frame': 4 obs. of 4 variables: $ V1: int 1 2 3 4 $ V2: int 5 6 7 8 $ V3: int 9 10 11 12 $ V4: num 0
Don't know if this is the intended result. In any case, you're probably better off using data.matrix, as > data.matrix(x) V1 V2 V3 V4 1 1 5 9 0 2 2 6 10 0 3 3 7 11 0 4 4 8 12 0 HTH, Andy > -----Original Message----- > From: Alberto Murta [mailto:[EMAIL PROTECTED] > Sent: Thursday, August 14, 2003 12:50 PM > To: [EMAIL PROTECTED] > Subject: [R] vectorization question > > > Dear all > > I recently noticed the following error when cohercing a > data.frame into a > matrix: > > > example <- matrix(1:12,4,3) > > example <- as.data.frame(example) > > example$V4 <- 0 > > example > V1 V2 V3 V4 > 1 1 5 9 0 > 2 2 6 10 0 > 3 3 7 11 0 > 4 4 8 12 0 > > example <- as.matrix(example) > Error in as.matrix.data.frame(example) : dim<- length of dims > do not match the > length of object > > However, if the column to be added has the right number of > lines, there's no > error: > > > example <- matrix(1:12,4,3) > > example <- as.data.frame(example) > > example$V4 <- rep(0,4) > > example > V1 V2 V3 V4 > 1 1 5 9 0 > 2 2 6 10 0 > 3 3 7 11 0 > 4 4 8 12 0 > > example <- as.matrix(example) > > example > V1 V2 V3 V4 > 1 1 5 9 0 > 2 2 6 10 0 > 3 3 7 11 0 > 4 4 8 12 0 > > Shouldn't it work well both ways? I checked the attributes > and dims of the > data frame and they are the same in both cases. Where's the > difference that > originates the error message? > Thanks in advance > > Alberto > > platform i686-pc-linux-gnu > arch i686 > os linux-gnu > system i686, linux-gnu > status > major 1 > minor 7.1 > year 2003 > month 06 > day 16 > language R > > > -- > Alberto G. Murta > Institute for Agriculture and Fisheries Research (INIAP-IPIMAR) > Av. Brasilia, 1449-006 Lisboa, Portugal | Phone: +351 > 213027062 Fax:+351 213015948 | > http://www.ipimar-iniap.ipimar.pt/pelagicos/ > > > ______________________________________________ > [EMAIL PROTECTED] mailing list > https://www.stat.math.ethz.ch/mailman/listinfo> /r-help > ------------------------------------------------------------------------------ Notice: This e-mail message, together with any attachments, contains information of Merck & Co., Inc. (Whitehouse Station, New Jersey, USA), and/or its affiliates (which may be known outside the United States as Merck Frosst, Merck Sharp & Dohme or MSD) that may be confidential, proprietary copyrighted and/or legally privileged, and is intended solely for the use of the individual or entity named on this message. If you are not the intended recipient, and have received this message in error, please immediately return this by e-mail and then delete it. ______________________________________________ [EMAIL PROTECTED] mailing list https://www.stat.math.ethz.ch/mailman/listinfo/r-help
