Sorry, Jeff. aggregate() is generic.
>From ?aggregate:
"## S3 method for class 'data.frame'
aggregate(x, by, FUN, ..., simplify = TRUE)"
Cheers,
Bert
Bert Gunter
Genentech Nonclinical Biostatistics
(650) 467-7374
"Data is not information. Information is not knowledge. And knowledge
is certainly not wisdom."
Clifford Stoll
On Thu, Mar 5, 2015 at 7:54 AM, Jeff Newmiller <jdnew...@dcn.davis.ca.us> wrote:
> The aggregate function applies FUN to vectors, not data frames. For example,
> the default "mean" function accepts a vector such as a column in a data frame
> and returns a scalar (well, a vector of length 1). Aggregate then calls this
> function once for each piece of the column(s) you give it. Your function
> wants two vectors, but aggregate does not understand how to give two inputs.
>
> (In the future, please follow R-help mailing list guidelines and post using
> plain text so your code does not get messed up.)
>
> You could use split to break your data frame into a list of data frames, and
> then sapply to extract the results you are looking for. I prefer to use the
> plyr or dplyr or data.table packages to do all this for me.
>
> d_rule <- function( DF ) {
> i <- which( DF$a==max( DF$a ) )
> if ( length( i ) == 1 ){
> DF[ i, "x" ]
> } else {
> min( DF[ , "x" ] ) # did you mean min( DF$x[i] ) ?
> }
> }
>
> dat <- data.frame( a=c(2,2,1,4,2,5,2,3,4,4)
> , x = c(1:10)
> , g = c(1,1,2,2,3,3,4,4,5,5)
> )
> # note that cbind on vectors creates a matrix
> # in a matrix all columns must be of the same type
> # but data frames generally have a variety of types
> # so don't use cbind when making a data frame
>
> library( dplyr )
>
> result <- dat %>% group_by( g ) %>% do( answer = d_rule( . ) ) %>%
> as.data.frame
>
> ---------------------------------------------------------------------------
> Jeff Newmiller The ..... ..... Go Live...
> DCN:<jdnew...@dcn.davis.ca.us> Basics: ##.#. ##.#. Live Go...
> Live: OO#.. Dead: OO#.. Playing
> Research Engineer (Solar/Batteries O.O#. #.O#. with
> /Software/Embedded Controllers) .OO#. .OO#. rocks...1k
> ---------------------------------------------------------------------------
> Sent from my phone. Please excuse my brevity.
>
> On March 4, 2015 2:02:06 PM PST, Typhenn Brichieri-Colombi via R-help
> <r-help@r-project.org> wrote:
>>Hello,
>>
>>I am trying to use the following custom function in an
>>aggregatefunction, but cannot get R to recognize my data. I’ve read the
>>help on function()and on aggregate() but am unable to solve my problem.
>>How can I get R torecognize the data inputs for the custom function
>>nested within aggregate()?
>>
>>My custom function is found below, as well as the errormessage I get
>>when I run it on a test data set (I will be using this functionon a
>>much larger dataset (over 600,000 rows))
>>
>>Thank you for your time and your help!
>>
>>
>>
>>d_rule<-function(a,x){
>>
>>i<-which(a==max(a))
>>
>>out<-ifelse(length(i)==1, x[i], min(x))
>>
>>return(out)
>>
>>}
>>
>>
>>
>>a<-c(2,2,1,4,2,5,2,3,4,4)
>>
>>x<-c(1:10)
>>
>>g<-c(1,1,2,2,3,3,4,4,5,5)
>>
>>dat<-as.data.frame(cbind(x,g))
>>
>>
>>
>>test<-aggregate(dat, by=list(g), FUN=d_rule,dat$a, dat$x)
>>
>>Error in dat$x : $ operator is invalid for atomic vectors
>>
>>
>>
>> [[alternative HTML version deleted]]
>>
>>______________________________________________
>>R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see
>>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@r-project.org mailing list -- To UNSUBSCRIBE and more, see
> 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@r-project.org mailing list -- To UNSUBSCRIBE and more, see
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.
