| % File src/library/grDevices/man/pretty.Date.Rd |
| % Part of the R package, https://www.R-project.org |
| % Copyright 2010-2016 R Core Team |
| % Distributed under GPL 2 or later |
| |
| \name{pretty.Date} |
| \title{Pretty Breakpoints for Date-Time Classes} |
| \alias{pretty.Date}%- keep alias{}es - such that ?pretty.Date works |
| \alias{pretty.POSIXt} |
| \usage{ |
| \method{pretty}{Date}(x, n = 5, min.n = n \%/\% 2, sep = " ", \dots) |
| \method{pretty}{POSIXt}(x, n = 5, min.n = n \%/\% 2, sep = " ", \dots) |
| } |
| \arguments{ |
| \item{x}{an object of class \code{"Date"} or \code{"POSIXt"} (i.e., |
| \code{"POSIXct"} or \code{"POSIXlt"}). } |
| \item{n}{integer giving the \emph{desired} number of intervals.} |
| \item{min.n}{nonnegative integer giving the \emph{minimal} number of |
| intervals.} |
| \item{sep}{character string, serving as a separator for certain |
| formats (e.g., between month and year). } |
| \item{\dots}{further arguments for compatibility with the generic, |
| ignored.} |
| } |
| \description{ |
| Compute a sequence of about \code{n+1} equally spaced \sQuote{nice} |
| values which cover the range of the values in \code{x}, possibly of |
| length one, when \code{min.n = 0} and there is only one unique |
| \code{x}. |
| } |
| %% \note{The current algorithm is geared towards small \code{n}, not |
| %% larger than say, 50 or 100. |
| %% } |
| \value{ |
| A vector (of the suitable class) of locations, with attribute |
| \code{"labels"} giving corresponding formatted character labels. |
| } |
| \seealso{ |
| \code{\link{pretty}} for the default method. |
| } |
| \examples{ |
| \donttest{% time-dependent |
| pretty(Sys.Date()) |
| pretty(Sys.time(), n = 10) |
| } |
| pretty(as.Date("2000-03-01")) # R 1.0.0 came in a leap year |
| |
| ## time ranges in diverse scales:% also in ../../../../tests/reg-tests-1c.R |
| require(stats) |
| steps <- setNames(, |
| c("10 secs", "1 min", "5 mins", "30 mins", "6 hours", "12 hours", |
| "1 DSTday", "2 weeks", "1 month", "6 months", "1 year", |
| "10 years", "50 years", "1000 years")) |
| x <- as.POSIXct("2002-02-02 02:02") |
| lapply(steps, |
| function(s) { |
| at <- pretty(seq(x, by = s, length = 2), n = 5) |
| attr(at, "labels") |
| }) |
| } |
| \keyword{dplot} |