<Ted.Harding <at> manchester.ac.uk> writes: > > On 12-Feb-10 13:14:29, Juan Tomas Sayago wrote: > > Dear list, > > I have a list with 1000 x1000 lines and columns
Lists have neither lines nor columns. Can you explain exactly what you have? E.g. show us the code that created your "list"? > do you know how I can > > convert it to matrrix or data.frame. > > Thanks. > > Juan > > as.data.frame() will convert it to a dataframe. If you then apply > as.matrix() to the result you will get a matrix: > > L <- list(X=c(1,2,3),Y=c(4,5,6),Z=c(7,8,9)) If you want a matrix as opposed to a data.frame (e.g. your list entries are all numeric), and the data set is large, this more efficient method might be useful: > matrix(unlist(L), nrow=3) [,1] [,2] [,3] [1,] 1 4 7 [2,] 2 5 8 [3,] 3 6 9 If it's not obvious to you what that does, consider: > unlist(L) X1 X2 X3 Y1 Y2 Y3 Z1 Z2 Z3 1 2 3 4 5 6 7 8 9 > matrix(unlist(L), nrow=3, byrow=TRUE) [,1] [,2] [,3] [1,] 1 2 3 [2,] 4 5 6 [3,] 7 8 9 > matrix(unlist(L), nrow=3, byrow=FALSE) [,1] [,2] [,3] [1,] 1 4 7 [2,] 2 5 8 [3,] 3 6 9 > L > # $X > # [1] 1 2 3 > # $Y > # [1] 4 5 6 > # $Z > # [1] 7 8 9 > > D <- as.data.frame(L) > D > # X Y Z > # 1 1 4 7 > # 2 2 5 8 > # 3 3 6 9 > > M <- as.matrix(D) > M > # X Y Z > # [1,] 1 4 7 > # [2,] 2 5 8 > # [3,] 3 6 9 > > Note that applying as.matrix() directly to the original L will > not work. It returns a list, not a matrix. > > Ted. > > -------------------------------------------------------------------- > E-Mail: (Ted Harding) <Ted.Harding <at> manchester.ac.uk> > Fax-to-email: +44 (0)870 094 0861 > Date: 12-Feb-10 Time: 13:40:32 > ------------------------------ XFMail ------------------------------ > > ______________________________________________ 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.