I\'m trying to merge multiple data frames by row names.
I know how to do it with two:
x = data.frame(a = c(1,2,3), row.names = letters[1:3])
y = data.fra
As an alternative to Reduce
and merge
:
If you put all the data frames into a list, you can then use grep
and cbind
to get the data frames with the desired row names.
## set up the data
> x <- data.frame(x1 = c(2,4,6), row.names = letters[1:3])
> y <- data.frame(x2 = c(3,6,9), row.names = letters[1:3])
> z <- data.frame(x3 = c(1,2,3), row.names = letters[1:3])
> a <- data.frame(x4 = c(4,6,8), row.names = letters[4:6])
> lst <- list(a, x, y, z)
## combine all the data frames with row names = letters[1:3]
> gg <- grep(paste(letters[1:3], collapse = ""),
sapply(lapply(lst, rownames), paste, collapse = ""))
> do.call(cbind, lst[gg])
## x1 x2 x3
## a 2 3 1
## b 4 6 2
## c 6 9 3