[R] difference of two rows

[clion]

Yes, thanks, that works perfectly!
great command....

b.



jholtman wrote:
> 
> Try this:
> 
>> x <- read.table(textConnection("ID YEAR
> + 13 2007
> + 15 2003
> + 15 2006
> + 15 2008
> + 21 2006
> + 21 2007"), header=TRUE)
>> x$diff <- ave(x$YEAR, x$ID, FUN=function(a) c(diff(a), NA))
>>
>> x
>   ID YEAR diff
> 1 13 2007   NA
> 2 15 2003    3
> 3 15 2006    2
> 4 15 2008   NA
> 5 21 2006    1
> 6 21 2007   NA
> 
> 
> On Wed, Nov 25, 2009 at 10:55 AM, clion <birte_2 at hotmail.com> wrote:
>>
>> Dear R user,
>> I'd like to calculate the difference of two rows, where "ID" is the same.
>> eg.: I've got the following dataframe:
>> ID YEAR
>> 13 2007
>> 15 2003
>> 15 2006
>> 15 2008
>> 21 2006
>> 21 2007
>>
>> and I'd like to get the difference, like this:
>> ID YEAR     diff
>> 13 2007      NA
>> 15 2003       3
>> 15 2006       2
>> 15 2008      NA
>> 21 2006       1
>> 21 2007      NA
>>
>> that should be fairly easy...I hope
>> Thanks for any helpful comments
>> B.
>>
>>
>>
>> --
>> View this message in context:
>> http://old.nabble.com/difference-of-two-rows-tp26515212p26515212.html
>> Sent from the R help mailing list archive at Nabble.com.
>>
>> ______________________________________________
>> 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.
>>
> 
> 
> 
> -- 
> Jim Holtman
> Cincinnati, OH
> +1 513 646 9390
> 
> What is the problem that you are trying to solve?
> 
> ______________________________________________
> 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.
> 
> 

-- 
View this message in context: http://old.nabble.com/difference-of-two-rows-tp26515212p26525340.html
Sent from the R help mailing list archive at Nabble.com.