rbind two data.frame preserving row order and row names

Question

I have a list of data.frame objects which i would like to row append to one another, ie merge(..., all=T). However, merge seems to remove

Answer 1

Since you know you are not actually merging, but just rbind-ing, maybe something like this will work. It makes use of rbind.fill from "plyr". To use it, specify a list of the data.frames you want to rbind.

RBIND <- function(datalist) {
  require(plyr)
  temp <- rbind.fill(datalist)
  rownames(temp) <- unlist(lapply(datalist, row.names))
  temp
}
RBIND(list(x, y))
#               a  b  c  d
# row_1         1  2  3  4
# another_row1  2  3  4  5
# row_2        10 20 30 NA
# another_row2 20 30 40 NA