| # File src/library/base/R/sets.R |
| # Part of the R package, https://www.R-project.org |
| # |
| # Copyright (C) 1995-2015 The R Core Team |
| # |
| # This program is free software; you can redistribute it and/or modify |
| # it under the terms of the GNU General Public License as published by |
| # the Free Software Foundation; either version 2 of the License, or |
| # (at your option) any later version. |
| # |
| # This program is distributed in the hope that it will be useful, |
| # but WITHOUT ANY WARRANTY; without even the implied warranty of |
| # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| # GNU General Public License for more details. |
| # |
| # A copy of the GNU General Public License is available at |
| # https://www.R-project.org/Licenses/ |
| |
| ## See the help for why as.vector is used: |
| ## it includes coercing factors. |
| union <- function(x, y) unique(c(as.vector(x), as.vector(y))) |
| |
| intersect <- function(x, y) |
| { |
| y <- as.vector(y) |
| unique(y[match(as.vector(x), y, 0L)]) |
| } |
| |
| setdiff <- function(x, y) |
| { |
| x <- as.vector(x) |
| y <- as.vector(y) |
| unique(if(length(x) || length(y)) x[match(x, y, 0L) == 0L] else x) |
| } |
| |
| ## speed optimization etc: R-devel, Jan.4-6, 2000; then again 15 yrs later |
| setequal <- function(x, y) |
| { |
| x <- as.vector(x) |
| y <- as.vector(y) |
| !( anyNA(match(x, y)) || anyNA(match(y, x)) ) |
| } |
| |
| ## same as %in% ( ./match.R ) but different arg names: |
| is.element <- function(el, set) match(el, set, 0L) > 0L |