# axTicks.POSIXct: Compute Axis Tickmark Locations (For POSIXct Axis) In AndriSignorell/DescTools: Tools for Descriptive Statistics

 axTicks.POSIXct R Documentation

## Compute Axis Tickmark Locations (For POSIXct Axis)

### Description

Compute pretty tickmark locations, the same way as R does internally. By default, gives the at values which axis.POSIXct(side, x) would use.

### Usage

``````axTicks.POSIXct(side, x, at, format, labels = TRUE, ...)

axTicks.Date(side = 1, x, ...)
``````

### Arguments

 `side` See axis. `x`, `at` A date-time or date object. `format` See strptime. `labels` Either a logical value specifying whether annotations are to be made at the tickmarks, or a vector of character strings to be placed at the tickpoints. `...` Further arguments to be passed from or to other methods.

### Details

axTicks has no implementation for POSIXct axis. This function fills the gap.

### Value

numeric vector of coordinate values at which axis tickmarks can be drawn.

### Author(s)

Andri Signorell <andri@signorell.net> simply copying R-Core code

`axTicks`, `axis.POSIXct`

### Examples

``````with(beaver1, {
time <- strptime(paste(1990, day, time %/% 100, time %% 100),
"%Y %j %H %M")
plot(time, temp, type = "l") # axis at 4-hour intervals.
# now label every hour on the time axis
plot(time, temp, type = "l", xaxt = "n")
r <- as.POSIXct(round(range(time), "hours"))
axis.POSIXct(1, at = seq(r[1], r[2], by = "hour"), format = "%H")
# place the grid
abline(v=axTicks.POSIXct(1, at = seq(r[1], r[2], by = "hour"), format = "%H"),
col="grey", lty="dotted")
})

``````

AndriSignorell/DescTools documentation built on Aug. 2, 2024, 3:15 a.m.