sfsmisc: tapplySimpl – R documentation

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tapplySimpl

More simplification in tapply() result

Description

For the case of more than two categories or indices (in INDEX), traditional tapply(*, simplify = TRUE) still returns a list when an array may seem more useful and natural. This is provided by tapplySimpl() if the function FUN() is defined such as to return a vector of the same length in all cases.

Usage

tapplySimpl(X, INDEX, FUN, ...)

Arguments

`X`	an atomic object, typically a vector. All these arguments are as in `tapply()` and are passed to `tapply(..)`.
`INDEX`	list of (typically more than one) factors, each of same length as `X`.
`FUN`	the function to be applied. For the result to be simplifiable, `FUN()` must return a vector of always the same length.
`...`	optional arguments to `FUN`.

Value

If the above conditions are satisfied, the list returned from r <- tapply(X, INDEX, FUN, ...) is simplified into an array of rank 1 + \#\{indices\}, i.e., 1+length(INDEX); otherwise, tapplySimpl() returns the list r, i.e., the same as tapply().

Author(s)

Martin Maechler, 14 Jun 1993 (for S-plus).

Examples

## Using tapply() would give a list (with dim() of a matrix);
  ## here we get 3-array:

  data(esoph)
  with(esoph, {
       mima <<- tapplySimpl(ncases/ncontrols, list(agegp, alcgp),  range)
       stopifnot(dim(mima) == c(2, nlevels(agegp), nlevels(alcgp)))
       })
  aperm(mima)

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