Hi r-help-boun...@r-project.org napsal dne 09.03.2009 11:29:41:
> > Dear all, > > I got one problem here and hoping someone can help me on this. Say I have a > 50 by 2 matrix and I don't know how to randomly select: > > 1. a pair of observations from the last 10th of the 50 observation from the > matrix. Use ?tail for ?nrow of matrix and ?sample this and select appropriate row from matrix > 2. how to select randomly an observation from the first 5 observations of > the second column in the matrix? the same principle applies here but use head instead. Regards Petr > > Thanks....hope to hear from someone soon > -- > View this message in context: http://www.nabble.com/How-to-select-randomly- > from-a-matrix--tp22410551p22410551.html > Sent from the R help mailing list archive at Nabble.com. > > ______________________________________________ > 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.
