[R] Filter according to the latest data

[jim holtman]

try this:

> x <- read.table(text = "                 No.          Change           Date
+ A              123           final                2013-01-15
+ B              123           error               2013-01-16
+ C              123           'bug fixed'       2013-01-17
+ D              111           final                2013-01-12"
+     , header = TRUE
+     , as.is = TRUE
+     )
> do.call(rbind, lapply(split(x, x$No.), function(.sec){
+     .sec[which(.sec$Date == max(.sec$Date))[1L], ]
+ }))
    No.    Change       Date
111 111     final 2013-01-12
123 123 bug fixed 2013-01-17


On Fri, Feb 1, 2013 at 3:04 AM, Mat <matthias.weber at fnt.de> wrote:
> Hello together,
>
> i have a data.frame, like this one:
>                  No.          Change           Date
> A              123           final                2013-01-15
> B              123           error               2013-01-16
> C              123           bug fixed       2013-01-17
> D              111           final                2013-01-12
>
> and now a want a new data.frame which includes only the newest entry for
> each number.
> The solution look like this:
>                  No.          Change           Date
> C              123           bug fixed       2013-01-17
> D              111           final                2013-01-12
>
> is there any way to filter my data.frame to the latest data, perhabs "max"?
>
> Thanks.
>
> Mat
>
>
>
> --
> View this message in context: http://r.789695.n4.nabble.com/Filter-according-to-the-latest-data-tp4657248.html
> Sent from the R help mailing list archive at Nabble.com.
>
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-- 
Jim Holtman
Data Munger Guru

What is the problem that you are trying to solve?
Tell me what you want to do, not how you want to do it.