[R] get latest dates for different people in a dataset

[Chel Hee Lee]

 > do.call(rbind, lapply(split(data, data$Name), function(x) 
x[order(x$CheckInDate),][nrow(x),]))
      Name CheckInDate Temp
John John  2014-04-01 99.0
Mary Mary  2014-03-01 98.1
Sam   Sam  2014-04-01 97.5
 >

Is this what you are looking for?  I hope this helps.

Chel Hee Lee

On 01/23/2015 05:43 PM, Tan, Richard wrote:
> Hi,
>
> Can someone help for a R question?
>
> I have a data set like:
>
> Name    CheckInDate      Temp
> John      1/3/2014              97
> Mary     1/3/2014              98.1
> Sam       1/4/2014              97.5
> John      1/4/2014              99
>
> I'd like to return a dataset that for each Name, get the row that is the latest CheckInDate for that person.  For the example above it would be
>
> Name    CheckInDate      Temp
> John      1/4/2014              99
> Mary     1/3/2014              98.1
> Sam       1/4/2014              97.5
>
>
> Thank you for your help!
>
> Richard
>
>
> 	[[alternative HTML version deleted]]
>
> ______________________________________________
> R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see
> 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.
>