uniqueL {sfsmisc} | R Documentation |
A version of unique
keeping enough information to
reverse (or invert) to the original data.
uniqueL(x, isuniq = !duplicated(x), need.sort = is.unsorted(x))
x |
numeric vector, of length n , say. |
isuniq |
logical vector of the same length as x . For the
reversion to work this should select at least all unique values of
x . |
need.sort |
logical indicating if x is not yet sorted.
Note that this argument exists only for speedup possibility when it
is known, and that it must be set correctly. |
list of two components,
ix |
integer vector of indices |
xU |
vector of values from x |
x[isuniq] === xU
and xU[ix] === x
.
Martin Maechler
Duplicated
from the sfsmisc package in
addition to the standard unique
and
duplicated
.
x0 <- c(1:3,2:7,8:4) str(r0 <- uniqueL(x0)) with(r0, xU[ix]) ## == x0 !