[R] create unique ID for each group

[arun]

HI Ye,

For the NA in ID column, 



Hi
dat1<- read.table(text="
ObsNumber     ID          Weight
     1                 0001         12
     2                 0001          13
     3                 0001           14
     4                  0002         16
      5                 0002         17
     6                   N/A          18   
",sep="",header=TRUE,colClass=c("numeric","character","numeric"),na.strings="N/A")
 unlist(lapply(split(dat1,dat1$ID),function(x) with(x,as.character(interaction(ID,seq_len(nrow(x)),sep="_")))),use.names=FALSE)
#[1] "0001_1" "0001_2" "0001_3" "0002_1" "0002_2"
A.K.
________________________________
From: Ye Lin <yelin at lbl.gov>
To: arun <smartpink111 at yahoo.com> 
Cc: R help <r-help at r-project.org> 
Sent: Tuesday, May 7, 2013 2:54 PM
Subject: Re: [R] create unique ID for each group



Thanks A.K. But I have "NA" in ID column, so when I apply the code, it gives me error saying the replacement as less rows than the data has. Anyway for ID=N/A, return sth like "N/A_1" in order as well?






On Tue, May 7, 2013 at 11:17 AM, arun <smartpink111 at yahoo.com> wrote:

H,
>Sorry, a mistake:
>dat1$UniqueID<-unlist(lapply(split(dat1,dat1$ID),function(x) with(x,as.character(interaction(ID,seq_len(nrow(x)),sep="_")))),use.names=FALSE)
>dat1
> # ObsNumber   ID Weight UniqueID
>#1         1 0001     12   0001_1
>#2         2 0001     13   0001_2
>#3         3 0001     14   0001_3
>#4         4 0002     16   0002_1
>#5         5 0002     17   0002_2
>
>dat2$UniqueID<-unlist(lapply(split(dat2,dat2$ID),function(x) with(x,as.character(interaction(ID,seq_len(nrow(x)),sep="_")))),use.names=FALSE)
>
>A.K.
>
>
>
>
>
>----- Original Message -----
>
>From: arun <smartpink111 at yahoo.com>
>To: Ye Lin <yelin at lbl.gov>
>Cc: R help <r-help at r-project.org>
>Sent: Tuesday, May 7, 2013 2:10 PM
>Subject: Re: [R] create unique ID for each group
>
>
>
>Hi,
>
>Try this:
>dat1<- read.table(text="
>ObsNumber     ID          Weight
>     1                 0001         12
>     2                 0001          13
>     3                 0001           14
>     4                  0002         16
>      5                 0002         17
>",sep="",header=TRUE,colClass=c("numeric","character","numeric"))
>dat2<- read.table(text="
>ID               Height
>0001            3.2
>0001             2.6
>0001             3.2
>0002             2.2
>0002              2.6
>",sep="",header=TRUE,colClass=c("character","numeric"))
>dat1$UniqueID<-with(dat1,as.character(interaction(ID,ObsNumber,sep="_")))
> dat2$UniqueID<-with(dat2,as.character(interaction(ID,rownames(dat2),sep="_")))
> dat2
>#    ID Height UniqueID
>#1 0001    3.2   0001_1
>#2 0001    2.6   0001_2
>#3 0001    3.2   0001_3
>#4 0002    2.2   0002_4
>#5 0002    2.6   0002_5
>A.K.
>
>
>
>----- Original Message -----
>From: Ye Lin <yelin at lbl.gov>
>To: R help <r-help at r-project.org>
>Cc:
>Sent: Tuesday, May 7, 2013 1:54 PM
>Subject: [R] create unique ID for each group
>
>Hey All,
>
>I have a dataset(dat1) like this:
>
>ObsNumber     ID          Weight
>     1                 0001         12
>     2                 0001          13
>     3                 0001           14
>     4                  0002         16
>      5                 0002         17
>
>And another dataset(dat2) like this:
>
>ID               Height
>0001            3.2
>0001             2.6
>0001             3.2
>0002             2.2
>0002              2.6
>
>I want to merge dat1 and dat2 based on "ID" in order, I know "match" only
>returns the first match it finds. So I am thinking create unique ID col in
>dat2 and dat2, then merge. But I dont know how to do that so it can be like
>this:
>
>dat1:
>
>ObsNumber     ID          Weight  UniqueID
>     1                 0001         12         0001_1
>     2                 0001          13        0001_2
>     3                 0001           14       0001_3
>     4                  0002         16         0002_1
>      5                 0002         17         0002_1
>
>dat2:
>
>ID               Height   UniqueID
>0001            3.2          0001_1
>0001             2.6         0001_2
>0001             3.2         0001_3
>0002             2.2         0002_1
>0002              2.6        0002_2
>
>Or if it is possible to merge dat1 and dat2 by matching "ID" but return the
>match in order that would be great!
>
>Thanks for your help!
>
>    [[alternative HTML version deleted]]
>
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