I defined a data.frame by a two-dimensional array.> aa = data.frame(rbind( 11:20, 1:10)) > aaX1 X2 X3 X4 X5 X6 X7 X8 X9 X10 1 11 12 13 14 15 16 17 18 19 20 2 1 2 3 4 5 6 7 8 9 10 Now I want to use the data in the second line of aa which from 1 to 10 to output.But I find that when I use the aa[[1]][1:10] and it seems be mistake. aa[[1]][1:10] [1] 11 1 NA NA NA NA NA NA NA NA But when I just indice one element of the dataframe .e.g.aa[[1]][2] It will be ok. How could I subset the data.frame data by lines? Thank you ? -- TANG Jie Email: totangjie@gmail.com Tel: 0086-2154896104 Shanghai Typhoon Institute,China [[alternative HTML version deleted]]
It is not clear to me from your description what exactly you are trying to do, but to get the numbers in the second line of aa you could use as.numeric(aa[2,]) HTH, Jorge.- On Wed, Aug 1, 2012 at 5:13 PM, Jie Tang <> wrote:> I defined a data.frame by a two-dimensional array. > > aa = data.frame(rbind( 11:20, 1:10)) > > aa > X1 X2 X3 X4 X5 X6 X7 X8 X9 X10 > 1 11 12 13 14 15 16 17 18 19 20 > 2 1 2 3 4 5 6 7 8 9 10 > > Now I want to use the data in the second line of aa which from 1 to 10 to > > output.But I find that when I use the aa[[1]][1:10] and it seems be > mistake. > aa[[1]][1:10] > [1] 11 1 NA NA NA NA NA NA NA NA > > But when I just indice one element of the dataframe .e.g.aa[[1]][2] > It will be ok. How could I subset the data.frame data by lines? > > Thank you ? > > -- > TANG Jie > Email: totangjie@gmail.com > Tel: 0086-2154896104 > Shanghai Typhoon Institute,China > > [[alternative HTML version deleted]] > > ______________________________________________ > 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. >[[alternative HTML version deleted]]
Please read An Introduction to R, which ships with every copy of R, where you will learn how to properly subscript data frames and lists, among other things. There is a reason for such tutorials -- they enable you to avoid elementary mistakes like this and wasting time and effort with such posts as this. -- Bert On Wed, Aug 1, 2012 at 2:13 PM, Jie Tang <totangjie at gmail.com> wrote:> I defined a data.frame by a two-dimensional array. >> aa = data.frame(rbind( 11:20, 1:10)) >> aa > X1 X2 X3 X4 X5 X6 X7 X8 X9 X10 > 1 11 12 13 14 15 16 17 18 19 20 > 2 1 2 3 4 5 6 7 8 9 10 > > Now I want to use the data in the second line of aa which from 1 to 10 to > > output.But I find that when I use the aa[[1]][1:10] and it seems be mistake. > aa[[1]][1:10] > [1] 11 1 NA NA NA NA NA NA NA NA > > But when I just indice one element of the dataframe .e.g.aa[[1]][2] > It will be ok. How could I subset the data.frame data by lines? > > Thank you ? > > -- > TANG Jie > Email: totangjie at gmail.com > Tel: 0086-2154896104 > Shanghai Typhoon Institute,China > > [[alternative HTML version deleted]] > > ______________________________________________ > R-help at 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.-- Bert Gunter Genentech Nonclinical Biostatistics Internal Contact Info: Phone: 467-7374 Website: http://pharmadevelopment.roche.com/index/pdb/pdb-functional-groups/pdb-biostatistics/pdb-ncb-home.htm