sfsmisc: inv.seq – R documentation

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inv.seq

Inverse seq() – Short Expression for Index Vector

Description

Compute a short expression for a given integer vector, typically an index, that can be expressed shortly, using : etc.

Usage

inv.seq(i)

Arguments

`i`	vector of (usually increasing) integers.

Value

a call (“the inside of an expression”) to be eval()ed to return the original i.

Author(s)

Martin Maechler, October 1995; more elegant implementation from Tony Plate.

Examples

(rr <- inv.seq(i1 <- c(3:12, 20:24, 27, 30:33)))
eval(rr)
stopifnot(eval(rr) == i1)

e2 <- expression(c(20:13, 3:12, -1:-4, 27, 30:31))
(i2 <- eval(e2))
(r2 <- inv.seq(i2))
stopifnot(all.equal(r2, e2[[1]]))

## Had {mapply()} bug in this example:
ii <- c(1:3, 6:9, 11:16)
stopifnot(identical(ii, eval(inv.seq(ii))))

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