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add identifier column by row

7 messages · Sarah Goslee, Don McKenzie, arun +1 more

Sarah Goslee
# 
You can use rep() to create the Date column, and data.frame() to combine it.

For your simple example,

newdata <- data.frame(dat, Date=rep(1:3, each=2))
On Tue, May 21, 2013 at 4:16 PM, Ye Lin <yelin at lbl.gov> wrote:

  
    

      
      
    

  


  


      

    

    

      
      

        


  

        

      Don McKenzie
    

    

      
      #
    

  


  

      
Do you want each number in "Date" to be repeated once (as in your  
example) or appear 48 times (so that you start over every 1440 rows,  
as in your request).

For the former,

rep(c(1:30),each=48)

fills the first 1440 rows.

        
On 21-May-13, at 1:16 PM, Ye Lin wrote:

        

            

      
      
      
    

        

      
      
    

        
Don McKenzie, Research Ecologist
Pacific Wildland Fire Sciences Lab
US Forest Service
phone: 206-732-7824

Affiliate Professor
School of Environmental and Forest Sciences
University of Washington

  
  


  


      

    

    

      
      

        


  

        

      Don McKenzie
    

    

      
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Duh -- I mean "for the latter"

        
On 21-May-13, at 1:25 PM, Don McKenzie wrote:

        

            

      
      
      
    

        

      
      
    

            

      
      
      
    

        

      
      
    

        
Don McKenzie, Research Ecologist
Pacific Wildland Fire Sciences Lab
US Forest Service
phone: 206-732-7824

Affiliate Professor
School of Environmental and Forest Sciences
University of Washington

  
  


  


      

    

    

      
      

        


  

        

      arun
    

    

      
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May be this helps:

dat<- read.table(text="
ID????? Var
1????????? 1
2????????? 4
3??????? 6
4??????? 7
5????????? 7
6????????? 8
7??? ?? 9 ??? 
",sep="",header=TRUE)
?dat$Date<-cumsum(seq_len(nrow(dat))%%2)
?dat
#? ID Var Date
#1? 1?? 1??? 1
#2? 2?? 4??? 1
#3? 3?? 6??? 2
#4? 4?? 7??? 2
#5? 5?? 7??? 3
#6? 6?? 8??? 3
#7? 7?? 9??? 4
A.K.


----- Original Message -----
From: Ye Lin <yelin at lbl.gov>
To: R help <r-help at r-project.org>
Cc: 
Sent: Tuesday, May 21, 2013 4:16 PM
Subject: [R] add identifier column by row

I want to add identifier column (Date) to a time series data frame. I want
to name the "Date" column be from 1 to 30 every 1440 rows.

Say I have a data like this (I simply my actual data here):

$dat

ID? ? ?  Var
1? ? ? ? ? 1
2? ? ? ? ? 4
3? ? ? ?  6
4? ? ? ?  7
5? ? ? ? ? 7
6? ? ? ? ? 8

How can I add identifier column (Date) from 1 to 3 every 2 rows and have
output like this:

ID? ? ?  Var? Date
1? ? ? ? ? 1? ? ? 1
2? ? ? ? ? 4? ?  1
3? ? ? ?  6? ? ? 2
4? ? ? ?  7? ? ? 2
5? ? ? ? ? 7? ?  3
6? ? ? ? ? 8? ? ? 3

Thanks,

??? [[alternative HTML version deleted]]

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