[R] merge two colums

[Robin Hankin]

Hi.

Use paste(... , sep="_") to create a new variable, then
data.frame()  to join them.

Note that you have to name the columns explicitly; the
default names are long for my tastes.


HTH

rksh



 > a <- data.frame(V1=1:3,V2=letters[1:3],V3=3:1,V4=100:102)
 > a
   V1 V2 V3  V4
1  1  a  3 100
2  2  b  2 101
3  3  c  1 102
 > data.frame(n1=a$V1,n2=paste(a$V2,a$V3,sep="_"),n4=a$V4)
   n1  n2  n4
1  1 a_3 100
2  2 b_2 101
3  3 c_1 102
 >



On 27 Feb 2007, at 11:31, Aimin Yan wrote:

> I have a data set like this
>
>> head(data.1A24_aa_model)
>      V1    V2 V3  V4 V5     V6
> 1 1A24 MODEL  1 ALA  1  84.47
> 2 1A24 MODEL  1 GLN  2  63.06
> 3 1A24 MODEL  1 TYR  3 107.72
> 4 1A24 MODEL  1 GLU  4  54.36
> 5 1A24 MODEL  1 ASP  5  67.01
> 6 1A24 MODEL  1 GLY  6 999.00
>
> I want to change this to the following format:
>
>     V1 V2 V3  V4 V5
> 1 1A24 MODEL  1 ALA _1  84.47
> 2 1A24 MODEL  1 GLN _2  63.06
> 3 1A24 MODEL  1 TYR _3 107.72
> 4 1A24 MODEL  1 GLU _4  54.36
> 5 1A24 MODEL  1 ASP _5  67.01
> 6 1A24 MODEL  1 GLY _6 999.00
>
> anyone know how to do this?
>
> Aimin
>
> ______________________________________________
> R-help at stat.math.ethz.ch 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.

--
Robin Hankin
Uncertainty Analyst
National Oceanography Centre, Southampton
European Way, Southampton SO14 3ZH, UK
  tel  023-8059-7743