[R] How to concatenate a several rows according with a column ?

[Rui Barradas]

Hello,

Inline.

Em 04-08-2012 09:34, David Winsemius escreveu:
>
> On Aug 3, 2012, at 10:00 AM, tgodoy wrote:
>
>> Hi, I'm a new user or R and I try to concatenate a several rows 
>> according
>> with the value in a column.
>>
>> this is my data.frame and I want to concatenate my data.frame 
>> according with
>> the column "b" and make a new data.frame with the information in the 
>> others
>> columns.
>>
> table1 <- <-read.table(text="
>         a                    b         c             d
> 1      E001234      TSA    IP234   like_domain
> 2      E001234      TSB    IP234   like_domain
> 3      E001234      TSC    IP234   like_domain
> 4      E001234      TSD    IP234   like_domain
> 5      E001235      TSA    IP235   two_domain
> 6      E001235      TSD    IP235   two_domain
> 7      E001235      TSS    IP235   two_domain
> 8      E001236      TSP    IP236   like_domain
> 9      E001236      TST    IP236   like_domain
> 10    E001237      TSV    IP237 
> simple_domain",header=TRUE,stringsAsFactors=FALSE)
>
> > aggrdat <- with(table1, aggregate(b, list(a,c,d), FUN=paste, sep=",") )
> > names(aggrdat) <- names(table1)[c(2:4,1)]

It's a column order issue, not a names one. Using Jean's form of aggregate,


aggrdat <- aggregate(b ~ a + c + d, data = table1, paste, sep=",")
(table2 <- aggrdat[, c(1, 4, 2, 3)])

Hope this helps,

Rui Barradas

> > aggrdat
>         b     c             d                  a
> 1 E001234 IP234   like_domain TSA, TSB, TSC, TSD
> 2 E001236 IP236   like_domain           TSP, TST
> 3 E001237 IP237 simple_domain                TSV
> 4 E001235 IP235    two_domain      TSA, TSD, TSS
>
> Swapping the column position is left as an exercise.
>