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Alexander Schwall

2010-Mar-02 17:53 UTC

[R] adding row ID numbers by group

Hello R community,

I am hoping for some help with the following problem.

I have a data frame containing various groups. These groups are identified
by a grouping variable. I would like to add a sequential ID number to each
group to later sort these individuals within each group by this ID number.

Here is what the final result should look like:

ID   group var2
1      1    1
2      1    2
3      1    3
4      1    4
1      2    5
2      2    6
3      2    7
4      2    8
5      2    9
1      3   10
2      3   11
3      3   12
4      3   13
5      3   14


I have created the following code to loop through this and compare a given
row with the following row for the grouping variable. If a given row would
be different from the then following row, the ID number would be reset and I
would start counting up again. The problem that I am encountering that at
the bottom of the data frame the if statement runs out of a condition
against which to compare the last row.

Here is what I did:

group<- c(1,1,1,1,2,2,2,2,2,3,3,3,3,3,3)
var2<- c(1,2,3,4,5,6,7,8,9,10,11,12,13,14,15)

data<-data.frame(group, var2)
data

#IDN is the desired ID number by group
IDN <-numeric(length(test$var2))
IDN


for (i in 1:(length(data$group))) {
      if(data[i,1] < (length(data$group))){
           if(data[i,1] == data[i+1,1]){
              IDN[i]<- sum(IDN[i-1],1)}
           else{
              IDN[i]<- -55} #for now an arbitrary value
      }
      if(data[i,1] == (length(data$group))) {
          IDN[i] <- 99 #for now an arbitrary value
      }
  }

IDN



Is there maybe an easier way to do this? Any thoughts would be very
appreciated since I am running out of ideas.

Thanks
Alexander

	[[alternative HTML version deleted]]

Henrique Dallazuanna

2010-Mar-02 17:58 UTC

head link

[R] adding row ID numbers by group

Try this:

data$ID <-  with(data, ave(group, group, FUN = seq))

On Tue, Mar 2, 2010 at 2:53 PM, Alexander Schwall
<alexander.schwall at gmail.com> wrote:> Hello R community,
>
> I am hoping for some help with the following problem.
>
> I have a data frame containing various groups. These groups are identified
> by a grouping variable. I would like to add a sequential ID number to each
> group to later sort these individuals within each group by this ID number.
>
> Here is what the final result should look like:
>
> ID ? group var2
> 1 ? ? ?1 ? ?1
> 2 ? ? ?1 ? ?2
> 3 ? ? ?1 ? ?3
> 4 ? ? ?1 ? ?4
> 1 ? ? ?2 ? ?5
> 2 ? ? ?2 ? ?6
> 3 ? ? ?2 ? ?7
> 4 ? ? ?2 ? ?8
> 5 ? ? ?2 ? ?9
> 1 ? ? ?3 ? 10
> 2 ? ? ?3 ? 11
> 3 ? ? ?3 ? 12
> 4 ? ? ?3 ? 13
> 5 ? ? ?3 ? 14
>
>
> I have created the following code to loop through this and compare a given
> row with the following row for the grouping variable. If a given row would
> be different from the then following row, the ID number would be reset and
I
> would start counting up again. The problem that I am encountering that at
> the bottom of the data frame the if statement runs out of a condition
> against which to compare the last row.
>
> Here is what I did:
>
> group<- c(1,1,1,1,2,2,2,2,2,3,3,3,3,3,3)
> var2<- c(1,2,3,4,5,6,7,8,9,10,11,12,13,14,15)
>
> data<-data.frame(group, var2)
> data
>
> #IDN is the desired ID number by group
> IDN <-numeric(length(test$var2))
> IDN
>
>
> for (i in 1:(length(data$group))) {
> ? ? ?if(data[i,1] < (length(data$group))){
> ? ? ? ? ? if(data[i,1] == data[i+1,1]){
> ? ? ? ? ? ? ?IDN[i]<- sum(IDN[i-1],1)}
> ? ? ? ? ? else{
> ? ? ? ? ? ? ?IDN[i]<- -55} #for now an arbitrary value
> ? ? ?}
> ? ? ?if(data[i,1] == (length(data$group))) {
> ? ? ? ? ?IDN[i] <- 99 #for now an arbitrary value
> ? ? ?}
> ?}
>
> IDN
>
>
>
> Is there maybe an easier way to do this? Any thoughts would be very
> appreciated since I am running out of ideas.
>
> Thanks
> Alexander
>
> ? ? ? ?[[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.
>


-- 
Henrique Dallazuanna
Curitiba-Paran?-Brasil
25? 25' 40" S 49? 16' 22" O

Felipe Carrillo

2010-Mar-02 18:08 UTC

head link

[R] adding row ID numbers by group

Like this?

group<- c(1,1,1,1,2,2,2,2,2,3,3,3,3,3,3)
var2<- c(1,2,3,4,5,6,7,8,9,10,11,12,13,14,15)
data<-data.frame(group, var2)
data
ddply(data,"group",transform,ID=1:length(group))
?
Felipe D. Carrillo
Supervisory Fishery Biologist
Department of the Interior
US Fish & Wildlife Service
California, USA



----- Original Message ----> From: Alexander Schwall <alexander.schwall at gmail.com>
> To: r-help at r-project.org
> Sent: Tue, March 2, 2010 9:53:19 AM
> Subject: [R] adding row ID numbers by group
> 
> Hello R community,
I am hoping for some help with the following > problem.
I have a data frame containing various groups. These groups are
> identifiedby a grouping variable. I would like to add a sequential ID number
> to eachgroup to later sort these individuals within each group by this ID
> number.
Here is what the final result should look like:

ID? > group var21? ? ? 1? ? 1
2? ? ? > 1? ? 23? ? ? 1? ? 3
4? ? > ? 1? ? 41? ? ? 2? ? 5
2? > ? ? 2? ? 6
3? ? ? 2? ? > 74? ? ? 2? ? 8
5? ? ? 2? > ? 91? ? ? 3? 10
2? ? ? 3? > 113? ? ? 3? 12
4? ? ? 3? > 135? ? ? 3? 14


I have created the following > code to loop through this and compare a given
row with the following row for > the grouping variable. If a given row would
be different from the then > following row, the ID number would be reset and I
would start counting up > again. The problem that I am encountering that at
the bottom of the data > frame the if statement runs out of a condition
against which to compare the > last row.
Here is what I did:

group<- > c(1,1,1,1,2,2,2,2,2,3,3,3,3,3,3)
var2<- > c(1,2,3,4,5,6,7,8,9,10,11,12,13,14,15)
data<-data.frame(group, > var2)data

#IDN is the desired ID number by group
IDN > <-numeric(length(test$var2))IDN


for (i in > 1:(length(data$group))) {
? ? ? if(data[i,1] < > (length(data$group))){
? ? ? ? ? if(data[i,1] == > data[i+1,1]){
? ? ? ? ? ? ? IDN[i]<- > sum(IDN[i-1],1)}? ? ? ? ? else{
? ? > ? ? ? ? ? IDN[i]<- -55} #for now an arbitrary 
> value? ? ? }
? ? ? if(data[i,1] == > (length(data$group))) {
? ? ? ? ? IDN[i] <- 99 > #for now an arbitrary value? ? ? }
? > }
IDN



Is there maybe an easier way to do this? Any > thoughts would be very
appreciated since I am running out of > ideas.
Thanks
Alexander

??? [[alternative HTML > version deleted]]
______________________________________________> ymailto="mailto:R-help at r-project.org" 
> href="mailto:R-help at r-project.org">R-help at r-project.org
mailing list
> href="https://stat.ethz.ch/mailman/listinfo/r-help" target=_blank
> >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.

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