[R] how to subset the data frame by lines

Bert Gunter gunter.berton at gene.com
Wed Aug 1 23:27:11 CEST 2012


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



More information about the R-help mailing list