sfsmisc: Duplicated – R documentation

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Duplicated

Counting-Generalization of duplicated()

Description

Duplicated() generalizes the duplicated method for vectors, by returning indices of “equivalence classes” for duplicated entries and returning nomatch (NA by default) for unique entries.

Note that duplicated() is not TRUE for the first time a duplicate appears, whereas Duplicated() only marks unique entries with nomatch (NA).

Usage

Duplicated(v, incomparables = FALSE, fromLast = FALSE, nomatch = NA_integer_)

Arguments

`v`	a vector, often character, factor, or numeric.
`incomparables`	a vector of values that cannot be compared, passed to both `duplicated()` and `match()`. `FALSE` is a special value, meaning that all values can be compared, and may be the only value accepted for methods other than the default. It will be coerced internally to the same type as `x`.
`fromLast`	logical indicating if duplication should be considered from the reverse side, i.e., the last (or rightmost) of identical elements would correspond to `duplicated=FALSE`.
`nomatch`	passed to `match()`: the value to be returned in the case when no match is found. Note that it is coerced to `integer`.

Value

an integer vector of the same length as v. Can be used as a factor, e.g., in split, tapply, etc.

Author(s)

Christoph Buser and Martin Maechler, Seminar fuer Statistik, ETH Zurich, Sep.2007

Examples

x <- c(9:12, 1:4, 3:6, 0:7)
data.frame(x, dup = duplicated(x),
              dupL= duplicated(x, fromLast=TRUE),
              Dup = Duplicated(x),
              DupL= Duplicated(x, fromLast=TRUE))

sfsmisc

Utilities from 'Seminar fuer Statistik' ETH Zurich

v1.1-11

GPL (>= 2)

Authors

Martin Maechler [aut, cre] (<https://orcid.org/0000-0002-8685-9910>), Werner Stahel [ctb] (Functions: compresid2way(), f.robftest(), last(), p.scales(), p.dnorm()), Andreas Ruckstuhl [ctb] (Functions: p.arrows(), p.profileTraces(), p.res.2x()), Christian Keller [ctb] (Functions: histBxp(), p.tachoPlot()), Kjetil Halvorsen [ctb] (Functions: KSd(), ecdf.ksCI()), Alain Hauser [ctb] (Functions: cairoSwd(), is.whole(), toLatex.numeric()*), Christoph Buser [ctb] (to function Duplicated()), Lorenz Gygax [ctb] (to function p.res.2fact()), Bill Venables [ctb] (Functions: empty.dimnames(), primes()), Tony Plate [ctb] (to inv.seq()), Isabelle Fl<fc>ckiger [ctb], Marcel Wolbers [ctb], Markus Keller [ctb], Sandrine Dudoit [ctb], Jane Fridlyand [ctb], Greg Snow [ctb] (to loessDemo()), Henrik Aa. Nielsen [ctb] (to loessDemo()), Vincent Carey [ctb], Ben Bolker [ctb], Philippe Grosjean [ctb], Fr<e9>d<e9>ric Ibanez [ctb], Caterina Savi [ctb], Charles Geyer [ctb], Jens Oehlschl<e4>gel [ctb]

Initial release

2021-04-03