hist.POSIXt {graphics}R Documentation

Histogram of a Date or Date-Time Object

Description

Method for hist applied to date or date-time objects.

Usage

## S3 method for class 'POSIXt':
hist(x, breaks, ..., plot = TRUE, freq = FALSE,
     start.on.monday = TRUE, format)

## S3 method for class 'Date':
hist(x, breaks, ..., plot = TRUE, freq = FALSE,
     start.on.monday = TRUE, format)

Arguments

x an object inheriting from class "POSIXt" or "Date".
breaks a vector of cut points or number giving the number of intervals which x is to be cut into or an interval specification, one of "days", "weeks", "months" or "years", plus "secs", "mins", "hours" for date-time objects.
... graphical parameters, or arguments to hist.default such as include.lowest, right and labels.
plot logical. If TRUE (default), a histogram is plotted, otherwise a list of breaks and counts is returned.
freq logical; if TRUE, the histogram graphic is a representation of frequencies, i.e, the counts component of the result; if FALSE, relative frequencies (“probabilities”) are plotted.
start.on.monday logical. If breaks = "weeks", should the week start on Mondays or Sundays?
format for the x-axis labels. See strptime.

Value

An object of class "histogram": see hist.

See Also

seq.POSIXt, axis.POSIXct, hist

Examples

hist(.leap.seconds, "years", freq = TRUE)
hist(.leap.seconds,
     seq(ISOdate(1970, 1, 10), ISOdate(2002, 1, 1), "5 years"))

## 100 random dates in a 10-week period
random.dates <- as.Date("2001/1/1") + 70*runif(100)
hist(random.dates, "weeks", format = "%d %b")

[Package graphics version 2.1.0 Index]