| # File src/library/base/R/jitter.R |
| # Part of the R package, https://www.R-project.org |
| # |
| # Copyright (C) 1995-2012 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/ |
| |
| ### Unimplemented Idea {for amount = NULL ?} |
| ### Really "optimal" (e.g. for rug()), use a non-constant amount, |
| ### e.g. use "d" = diff(xx) BEFORE taking min()... |
| |
| jitter <- function(x, factor = 1, amount=NULL) |
| { |
| if(length(x) == 0L) |
| return(x) |
| if(!is.numeric(x)) |
| stop("'x' must be numeric") |
| z <- diff(r <- range(x[is.finite(x)])) |
| if(z == 0) z <- abs(r[1L]) |
| if(z == 0) z <- 1 |
| |
| if(is.null(amount)) { # default: Find 'necessary' amount |
| d <- diff(xx <- unique(sort.int(round(x, 3 - floor(log10(z)))))) |
| d <- if(length(d)) min(d) else if(xx != 0) xx/10 else z/10 |
| amount <- factor/5 * abs(d) |
| } else if(amount == 0) # only then: S compatibility |
| amount <- factor * (z/50) |
| |
| x + stats::runif(length(x), - amount, amount) |
| } |