This function works similar to unique, but provides additional information about which elements of original input 'x' are repeatd by providing indexes realtoe to the input.
firstOfRepeated makes list with 3 elements : $indRepeated.. index for first of repeated 'x', $indUniq.. index of all unique + first of repeated, $indRedund.. index of all redundant entries, ie non-unique (wo 1st).
Used for reducing data to non-redundant status, however, for large numeric input the function nonAmbiguousNum() may perform better/faster.
NAs won't be considered (NAs do not appear in reported index of results), see also firstOfRepLines() .
Usage
firstOfRepeated(x)
Arguments
x
(charcter or numeric) main input
Value
list with indices: $indRepeated, $indUniq, $indRedund
# NOT RUN {x <- c(letters[c(3,2:4,8,NA,3:1,NA,5:4)]); names(x) <- 100+(1:length(x))
firstOfRepeated(x)
x[firstOfRepeated(x)$indUniq] # only unique with names# }