From the signature:
ldply(.data, .fun = NULL, ..., .progress = "none",
.inform = FALSE, .parallel = FALSE, .paropts = NULL)
ldply
doesn't take a .variables
argument like dlply
(and, it's not implied by the ...
as they are passed as args to .fun
).
Pretty sure this gets what you want (and, I'm fairly sure there are better ways to do it):
extract_SEAc <- function(e) {
data.frame(e$xSEAc, e$ySEAc)
}
e2 <- ldply(ell, extract_SEAc)
head(e2)
Site SizeClass e.xSEAc e.ySEAc
1 1 Big -2.462496 12.28447
2 1 Big -2.473344 12.24886
3 1 Big -2.484814 12.21326
4 1 Big -2.496901 12.17769
5 1 Big -2.509601 12.14216
6 1 Big -2.522911 12.10669