Try help("read.delim") - always a good strategy before using a function for
the first time:In it, you will find: "Using row.names = NULL forces row numbering. Missing or NULL row.names generate row names that are considered to be 'automatic' (and not preserved by as.matrix)." ---------------------------------------------- David L Carlson Associate Professor of Anthropology Texas A&M University College Station, TX 77843-4352 > -----Original Message----- > From: r-help-boun...@r-project.org [mailto:r-help-bounces@r- > project.org] On Behalf Of Ed Siefker > Sent: Monday, June 04, 2012 12:47 PM > To: r-help@r-project.org > Subject: [R] Why do I have a column called row.names? > > I'm trying to read in a tab separated table with read.delim(). > I don't particularly care what the row names are. > My data file looks like this: > > > start stop Symbol Insert sequence Clone End Pair FISH > 203048 67173930 ABC8-43024000D23 TI:993812543 > TI:993834585 > 255176 87869359 ABC8-43034700N15 TI:995224581 > TI:995237913 > 1022033 1060472 ABC27-1253C21 TI:2094436044 TI:2094696079 > 1022033 1061172 ABC23-1388A1 TI:2120730727 TI:2121592459 > > > > I have to do something with row.names because my first column has > duplicate entries. So I read in the file like this: > > > BACS<-read.delim("testdata.txt", row.names=NULL, fill=TRUE) > > head(BACS) > row.names start stop Symbol Insert.sequence > Clone.End.Pair > 1 203048 67173930 ABC8-43024000D23 NA TI:993812543 > TI:993834585 > 2 255176 87869359 ABC8-43034700N15 NA TI:995224581 > TI:995237913 > 3 1022033 1060472 ABC27-1253C21 NA TI:2094436044 > TI:2094696079 > 4 1022033 1061172 ABC23-1388A1 NA TI:2120730727 > TI:2121592459 > FISH > 1 NA > 2 NA > 3 NA > 4 NA > > > Why is there a column named "row.names"? I've tried a few different > ways of invoking this, but I always get the first column named > row.names, > and the rest of the columns shifted by one. > > Obviously I could fix this by using row.names<-, but I'd like to > understand > why this happens. Any insight? > > ______________________________________________ > 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. ______________________________________________ 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.
