Thank you Duncan. A follow-up question is, how can I achieve the desired result in the earlier email? (i.e. Add the resulting vectors as a new column to the existing data.frame?) I tried the following:
testframe$newcolumn<-apply(testframe,1,function(x)testfun(x[1],x[2])) but I am getting the following error: Error in `$<-.data.frame`(`*tmp*`, "vecss", value = c(2, 3, 4, 3, 4, 5 : replacement has 3 rows, data has 2 Thanks for the help. On Sun, Jun 10, 2012 at 12:02 PM, Duncan Murdoch <murdoch.dun...@gmail.com> wrote: > On 12-06-10 6:41 AM, Onur Uncu wrote: >> >> R-Help community, >> >> I understand that data.frames can hold elements of type double, string >> etc but NOT objects (such as a matrix etc). > > > That is incorrect. Dataframes can hold list vectors. For example: > > A <- data.frame(x = 1:3) > A$y <- list(matrix(1, 2,2), matrix(2, 3,3), matrix(3,4,4)) > > A[1,2] will now extract the 2x2 matrix, A[2,2] will extract the 3x3, etc. > > Duncan Murdoch > > This is not convenient for >> >> me in the following situation. I have a function that takes 2 inputs >> and returns a vector: >> >> testfun<- function (x,y) seq(x,y,1) >> >> I have a data.frame defined as follows: >> >> testframe<-data.frame(xvalues=c(2,3),yvalues=c(4,5)) >> >> I would like to apply testfun to every row of testframe and then >> create a new column in the data.frame which holds the returned vectors >> as objects. Why do I want this? Because the returned vectors are an >> intermediate step towards further calculations. It would be great to >> keep adding new columns to the data.frame with the intermediate >> objects. But this is not possible since data.frames can not hold >> objects as elements. What do you suggest as an elegant solution in >> this scenario? Thank you for any help! >> >> >> >> >> >> >> >> >> I would love to hear if forum >> >> ______________________________________________ >> 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. > > ______________________________________________ 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.
