Filter according to the latest data

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
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

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Filter according to the latest data

Thread (5 messages)