Laura: When posting to this list, it is best to provide a small example. This will facilitate better help. Here is an example of what you want to do.
> mat <- matrix(rnorm(10), ncol=2) > mat [,1] [,2] [1,] -0.1418628 -1.4559344 [2,] 0.4022863 1.4727494 [3,] 0.0158310 0.3471318 [4,] 0.3962089 -0.5179074 [5,] 1.8098082 0.7238309 ### Remove rows 2 and 3 > (newMat <- mat[c(-2,-3),]) [,1] [,2] [1,] -0.1418628 -1.4559344 [2,] 0.3962089 -0.5179074 [3,] 1.8098082 0.7238309 I don't know what you mean about the second part (match a string on a list). So, I didn't do anything with that > -----Original Message----- > From: r-help-boun...@r-project.org > [mailto:r-help-boun...@r-project.org] On Behalf Of Laura > Rodriguez Murillo > Sent: Friday, February 06, 2009 10:26 AM > To: r-help@r-project.org > Subject: [R] how to delete specific rows in a data frame > where the firstcolumn matches any string from a list > > Hi, > > I'm new in the mailing list but I would appreciate if you > could help me with this: > I have a big matrix from where I need to delete specific > rows. The second entry on these rows to delete should match > any string within a list (other file with just one column). > Thank you so much! > > Laura > > ______________________________________________ > 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.