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Filter according to the latest data

Hi,
Perhaps, (#Untested)
do.call(rbind,lapply(split(dat1,dat1$No),function(x) tail(x,1)))

#or
library(plyr)
ddply(dat1,.(No), function(x) x[nrow(x),])

A.K.


----- Original Message -----
From: Mat <matthias.weber at fnt.de>
To: r-help at r-project.org
Cc: 
Sent: Friday, February 1, 2013 3:04 AM
Subject: [R] Filter according to the latest data

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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