[R] data frame manipulation

[Jeff Newmiller]

Depending what you really want to achieve, the following may be useful or 
educational:

dat$ID2x <- with( dat, ave( rep( 1, nrow( dat ) ), ID, USE, FUN=cumsum ) )
dat$ID2y <- dat$ID2x
dat$ID2y[ dat$USE != "001" ] <- NA

On Thu, 20 Feb 2014, arun wrote:

> Hi,
> Try:
> dat$ID2 <- with(dat,ave(seq_along(USE),ID,FUN=function(x){x1 <- USE[x] =='001'; ifelse(!x1,'',cumsum(x1))}))
> A.K.
>
>
>
>
> On Thursday, February 20, 2014 3:31 PM, Pedro Mardones <mardones.p at gmail.com> wrote:
> Dear R community;
>
> I'm kind of stuck with the following situation and would appreciate any
> hint. Let's assume I have the following data frame:
>
> dat <- data.frame(ID = c(rep("01",18), rep("02",16)), USE = c(c("001","004",
> "005","007","001","004","005","007","012","001","004","005","007","001","004",
> "005","007","012"),c("004","005","007","013","001","004","005","007","001","004",
> "005","007","001","004","005","007")),ID2 = "")
>
> What I would like to achieve is to number all the "001" occurrences in USE
> for each ID individually and store them in ID2. In other words, something
> like this:
>
>    ID USE ID2
> 1  01 001  1
> 2  01 004
> 3  01 005
> 4  01 007
> 5  01 001   2
> 6  01 004
> 7  01 005
> 8  01 007
> 9  01 012
> 10 01 001   3
> 11 01 004
> 12 01 005
> 13 01 007
> 14 01 001   4
> 15 01 004
> 16 01 005
> 17 01 007
> 18 01 012
> 19 02 004
> 20 02 005
> 21 02 007
> 22 02 013
> 23 02 001    1
> 24 02 004
> 25 02 005
> 26 02 007
> 27 02 001    2
> 28 02 004
> 29 02 005
> 30 02 007
> 31 02 001    3
> 32 02 004
> 33 02 005
> 34 02 007
>
> Thanks again,
> Pedro
>
>     [[alternative HTML version deleted]]
>
> ______________________________________________
> R-help at 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.
>
>
> ______________________________________________
> R-help at 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.
>

---------------------------------------------------------------------------
Jeff Newmiller                        The     .....       .....  Go Live...
DCN:<jdnewmil at dcn.davis.ca.us>        Basics: ##.#.       ##.#.  Live Go...
                                       Live:   OO#.. Dead: OO#..  Playing
Research Engineer (Solar/Batteries            O.O#.       #.O#.  with
/Software/Embedded Controllers)               .OO#.       .OO#.  rocks...1k
---------------------------------------------------------------------------