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Last data update: 2014.03.03

R: Compute Axis Tickmark Locations (For POSIXct Axis)

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, ...)

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

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")
})

Results


R version 3.3.1 (2016-06-21) -- "Bug in Your Hair"
Copyright (C) 2016 The R Foundation for Statistical Computing
Platform: x86_64-pc-linux-gnu (64-bit)

R is free software and comes with ABSOLUTELY NO WARRANTY.
You are welcome to redistribute it under certain conditions.
Type 'license()' or 'licence()' for distribution details.

R is a collaborative project with many contributors.
Type 'contributors()' for more information and
'citation()' on how to cite R or R packages in publications.

Type 'demo()' for some demos, 'help()' for on-line help, or
'help.start()' for an HTML browser interface to help.
Type 'q()' to quit R.

> library(DescTools)
> png(filename="/home/ddbj/snapshot/RGM3/R_CC/result/DescTools/axTicks.POSIXct.Rd_%03d_medium.png", width=480, height=480)
> ### Name: axTicks.POSIXct
> ### Title: Compute Axis Tickmark Locations (For POSIXct Axis)
> ### Aliases: axTicks.POSIXct
> ### Keywords: aplot chron
> 
> ### ** 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")
+ })
> 
> 
> 
> 
> 
> 
> dev.off()
null device 
          1 
>