[R] group data

[arun]

Hi,
dat1<- read.table(text="
ID  Value
AL1  1
AL2  2
CA1  3
CA4  4
",sep="",header=TRUE,stringsAsFactors=FALSE) 

dat2<- dat1

dat1$State<-gsub("\\d+","",dat1$ID)
dat1
#   ID Value State
#1 AL1     1    AL
#2 AL2     2    AL
#3 CA1     3    CA
#4 CA4     4    CA


#or
library(stringr)
dat2$State<-str_replace(dat2$ID,"\\d+","")
A.K.


Hey, 

I have a dataset and I want to identify the records by groups for further 
use in ggplot. 

Here is a sample data: 

ID  Value 
AL1  1 
AL2  2 
CA1  3 
CA4  4 

I want to identify all the records that in the same state (AL1 AND A2), 
group them as "AL", and do the same for CA1 and CA4. How can I have an 
output like: 

ID  Value State 
AL1  1       AL 
AL2  2      AL 
CA1  3      CA 
CA4  4     CA 

Thanks for your help!