sets.Rd 1.82 KB
 Radford Neal committed May 18, 2013 1 2 % File src/library/base/man/sets.Rd % Part of the R package, http://www.R-project.org  Radford Neal committed Aug 26, 2016 3 % Copyright 1995-2011 R Core Team  Radford Neal committed May 18, 2013 4 5 6 7 8 9 10 11 % Distributed under GPL 2 or later \name{sets} \alias{union} \alias{intersect} \alias{setdiff} \alias{is.element} \alias{setequal}  Radford Neal committed May 18, 2013 12 13 14 15 16 \concept{set operations} \concept{sets} % not that useful for searches, but requested in a bug report \alias{intersection} \concept{difference}  Radford Neal committed May 18, 2013 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 \title{Set Operations} \usage{ union(x, y) intersect(x, y) setdiff(x, y) setequal(x, y) is.element(el, set) } \arguments{ \item{x, y, el, set}{vectors (of the same mode) containing a sequence of items (conceptually) with no duplicated values.} } \description{ Performs \bold{set} union, intersection, (asymmetric!) difference, equality and membership on two vectors. } \details{ Each of \code{union}, \code{intersect}, \code{setdiff} and \code{setequal} will discard any duplicated values in the arguments, and they apply \code{\link{as.vector}} to their arguments (and so in particular coerce factors to character vectors). \code{is.element(x, y)} is identical to \code{x \%in\% y}. } \value{ A vector of the same \code{\link{mode}} as \code{x} or \code{y} for \code{setdiff} and \code{intersect}, respectively, and of a common mode for \code{union}. A logical scalar for \code{setequal} and a logical of the same length as \code{x} for \code{is.element}. } \seealso{ \code{\link{\%in\%}} \sQuote{\link{plotmath}} for the use of \code{union} and \code{intersect} in plot annotation. } \examples{ (x <- c(sort(sample(1:20, 9)),NA)) (y <- c(sort(sample(3:23, 7)),NA)) union(x, y) intersect(x, y) setdiff(x, y) setdiff(y, x) setequal(x, y) ## True for all possible x & y : setequal( union(x,y), c(setdiff(x,y), intersect(x,y), setdiff(y,x))) is.element(x, y)# length 10 is.element(y, x)# length 8 } \keyword{misc}