axis.POSIXct {base}R Documentation

Date-time Plotting Functions

Description

Functions to manipulate objects of classes "POSIXlt" and "POSIXct" representing calendar dates and times (to the nearest second).

Usage

plot.POSIXct(x, y, xlab = "", ...)
plot.POSIXlt(x, y, xlab = "", ...)
axis.POSIXct(side, x, format, ...)

Arguments

x A date-time object.
y numeric values to be plotted against x.
xlab a character string giving the label for the x axis.
side See axis.
format See strptime.
... Further arguments to be passed from or to other methods.

Details

The functions plot against an x-axis of date-times. axis.POSIXct works quite hard to choose suitable time units (years, months, days, hours, minutes or seconds) and a sensible output format, but this can be overridden by supplying a format specification.

See Also

DateTimeClasses for details of the classes.

Examples

library(MASS)
data(beav1)
attach(beav1)
time <- strptime(paste(day, time %/% 100, time %% 100),
                 "%j %H %M")
plot(time, temp, type="l") # axis at 4-hour intervals.
detach("beav1")

plot(.leap.seconds, 1:22, type="n", yaxt="n",
     xlab="leap seconds", ylab="")
rug(.leap.seconds)