Named list of data.frames to data.frame with names
Hello, There's nothing inelegant in your solution, you're using vectorized instructions. But there's a bug. The argument to rep should be 'each', not 'times'. l2$name <- rep(names(l), each=sapply(l,nrow)) Hope this helps, Rui Barradas Em 30-10-2012 08:16, Mark Payne escreveu:
Hi,
I very frequently end up in a situation where I have a named list of
data.frames that I wish to combine. e.g.
l <- list(A=data.frame(x=rnorm(5),
y=rnorm(5)),
B=data.frame(x=rnorm(3),y=rnorm(3)),
C=data.frame(x=rnorm(4),y=rnorm(4)),
D=data.frame(x=rnorm(7),y=rnorm(7)))
I would like to combine these data.frames into a single data.frame,
with the column-names. This is easy with rbind and do.call
l2 <- do.call(rbind,l)
However, I would also like l2 to contain a column containing the names
in the original list? Is there a more elegant way to do this than:
l2 <- do.call(rbind,l)
l2$name <- rep(names(l),times=sapply(l,nrow))
Mark
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