| % File src/library/graphics/man/hist.POSIXt.Rd |
| % Part of the R package, https://www.R-project.org |
| % Copyright 1995-2016 R Core Team |
| % Distributed under GPL 2 or later |
| |
| \name{hist.POSIXt} |
| \alias{hist.POSIXt} |
| \alias{hist.Date} |
| \title{Histogram of a Date or Date-Time Object} |
| \description{ |
| Method for \code{\link{hist}} applied to date or date-time objects. |
| } |
| \usage{ |
| \method{hist}{POSIXt}(x, breaks, \dots, |
| xlab = deparse(substitute(x)), |
| plot = TRUE, freq = FALSE, |
| start.on.monday = TRUE, format, right = TRUE) |
| |
| \method{hist}{Date}(x, breaks, \dots, |
| xlab = deparse(substitute(x)), |
| plot = TRUE, freq = FALSE, |
| start.on.monday = TRUE, format, right = TRUE) |
| } |
| \arguments{ |
| \item{x}{an object inheriting from class \code{"POSIXt"} or \code{"Date"}.} |
| \item{breaks}{ |
| a vector of cut points \emph{or} number giving the number of |
| intervals which \code{x} is to be cut into \emph{or} an |
| interval specification, one of \code{"days"}, \code{"weeks"}, |
| \code{"months"}, \code{"quarters"} or \code{"years"}, |
| plus \code{"secs"}, \code{"mins"}, \code{"hours"} for |
| date-time objects. |
| } |
| \item{\dots}{\link{graphical parameters}, or arguments to |
| \code{\link{hist.default}} such as \code{include.lowest}, |
| \code{right} and \code{labels}.} |
| \item{xlab}{a character string giving the label for the x axis, if plotted.} |
| \item{plot}{logical. If \code{TRUE} (default), a histogram is |
| plotted, otherwise a list of breaks and counts is returned.} |
| \item{freq}{logical; if \code{TRUE}, the |
| histogram graphic is a representation of frequencies, i.e, |
| the \code{counts} component of the result; if \code{FALSE}, |
| \emph{relative} frequencies (probabilities) are plotted.} |
| \item{start.on.monday}{logical. If \code{breaks = "weeks"}, should the |
| week start on Mondays or Sundays?} |
| \item{format}{for the x-axis labels. See \code{\link{strptime}}.} |
| \item{right}{logical; if \code{TRUE}, the histogram cells are |
| right-closed (left open) intervals.} |
| } |
| \details{ |
| Note that unlike the default method, \code{breaks} is a required argument. |
| |
| Using \code{breaks = "quarters"} will create intervals of 3 calendar |
| months, with the intervals beginning on January 1, April 1, |
| July 1 or October 1, based upon \code{min(x)} as appropriate. |
| |
| With the default \code{right = TRUE}, breaks will be set |
| on the last day of the previous period when \code{breaks} is |
| \code{"months"}, \code{"quarters"} or \code{"years"}. Use |
| \code{right = FALSE} to set them to the first day of the |
| interval shown in each bar. |
| } |
| \value{ |
| An object of class \code{"histogram"}: see \code{\link{hist}}. |
| } |
| \seealso{ |
| \code{\link{seq.POSIXt}}, \code{\link{axis.POSIXct}}, \code{\link{hist}} |
| } |
| \examples{ |
| hist(.leap.seconds, "years", freq = TRUE) |
| hist(.leap.seconds, |
| seq(ISOdate(1970, 1, 1), ISOdate(2020, 1, 1), "5 years")) |
| rug(.leap.seconds, lwd=2) |
| |
| ## 100 random dates in a 10-week period |
| random.dates <- as.Date("2001/1/1") + 70*stats::runif(100) |
| hist(random.dates, "weeks", format = "\%d \%b") |
| } |
| \keyword{chron} |
| \keyword{dplot} |
| \keyword{hplot} |