On Mon, Oct 4, 2010 at 2:39 PM, Gabor Grothendieck
<ggrothendi...@gmail.com> wrote:
> On Mon, Oct 4, 2010 at 1:54 PM, Dylan Miracle <dylan.mira...@gmail.com> wrote:
>> Hello,
>>
>> I have a two column dataframe that
>> has entries that look like this:
>>
>> 2315100 NR_024005,NR_024004,AK093685
>> 2315106 DQ786314
>>
>> and I want to change this to look like this:
>>
>> 2315100 NR_024005
>> 2315100 NR_024004
>> 2315100 AK093685
>> 2315106 DQ786314
>>
>> I can do this with the following "for" loop but the dataframe (GPL)
>> has ~140,000 rows and this takes about 15 minutes:
>
> Try this assuming that the columns of GPL are character. You may need
> to use as.character first if they are factor:
>
> library(reshape2)
> V2 <- strsplit(GPL$V2, ",")
> names(V2) <- GPL$V1
> melt(V2)
We alternately use stack or lattice's make.groups so the solution becomes:
V2 <- strsplit(GPL$V2, ",")
names(V2) <- GPL$V1
# followed by one of these three
stack(V2)
library(reshape2)
melt(V2)
library(lattice)
do.call("make.groups", V2)
--
Statistics & Software Consulting
GKX Group, GKX Associates Inc.
tel: 1-877-GKX-GROUP
email: ggrothendieck at gmail.com
______________________________________________
R-help@r-project.org mailing list
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.
