Message-ID: <NDEKCIMKLDKMBAAA@mailcity.com>
Date: 2003-04-16T18:27:28Z
From: Remko Duursma
Subject: making a dataframe out of lapply() result
Mahbub's solution
data.frame(t(sapply(...)))
is much faster than
do.call("rbind", lapply(...))
as tested on a larger dataset.
Thanks everyone,
Remko Duursma
--
On Tue, 15 Apr 2003 22:10:28
Mahbub Latif wrote:
>you can try this,...
>data.frame(t(sapply(tester.L, function(x) x <- x[1,]
>)))
>
>Mahbub.
>
>--- Remko Duursma <den.duurs at lycos.com> wrote:
>> Dear R-helpers,
>>
>> i have a question on how to vectorize this problem:
>>
>> i have a dataframe:
>>
>> tester <-
>> data.frame(groups=c("A","A","B","B","C","C"),
>> one=c(1,1,2,2,3,3), two=c(6,6,7,7,8,8))
>>
>> # i split it into a list
>> tester.L <- split(tester, tester$groups)
>>
>> # And want to keep only the first item in each:
>> lapply(tester.L, function(x) x <- x[1,] )
>>
>>
>> How do i make a dataframe out of the last result,
>> which looks like "tester", without looping? (i can
>> use rbind in a for loop, but is rather slow)
>>
>> thanks for your help,
>>
>> Remko Duursma
>>
>>
>>
>____________________________________________________________
>> Get advanced SPAM filtering on Webmail or POP Mail
>> ... Get Lycos Mail!
>>
>> ______________________________________________
>> R-help at stat.math.ethz.ch mailing list
>>
>https://www.stat.math.ethz.ch/mailman/listinfo/r-help
>
>
>__________________________________________________
>Do you Yahoo!?
>http://search.yahoo.com
>