# axisTicks

0th

Percentile

##### Compute Pretty Axis Tick Scales

Compute pretty axis scales and tick mark locations, the same way as traditional R graphics do it. This is interesting particularly for log scale axes.

Keywords
dplot
##### Usage
axisTicks(usr, log, axp = NULL, nint = 5) .axisPars(usr, log = FALSE, nintLog = 5)
##### Arguments
usr
numeric vector of length 2, with c(min, max) axis extents.
log
logical indicating if a log scale is (thought to be) in use.
axp
numeric vector of length 3, c(mi, ma, n.), with identical meaning to par("?axp") (where ? is x or y), namely “pretty” axis extents, and an integer code n..
nint, nintLog
positive integer value indicating (approximately) the desired number of intervals. nintLog is used only for the case log = TRUE.
##### Details

axisTicks(usr, *) calls .axisPars(usr, ..) when axp is missing (or NULL).

##### Value

axisTicks() returns a numeric vector of potential axis tick locations, of length approximately nint+1..axisPars() returns a list with components
axp
numeric vector of length 2, c(min., max.), of pretty axis extents.
n
integer (code), with the same meaning as par("?axp").

axTicks; axis, and par (from the graphics package).
library(grDevices) ##--- Demonstrating correspondence between graphics' ##--- axis() and the graphics-engine agnostic axisTicks() : require("graphics") plot(10*(0:10)); (pu <- par("usr")) aX <- function(side, at, ...) axis(side, at = at, labels = FALSE, lwd.ticks = 2, col.ticks = 2, tck = 0.05, ...) aX(1, print(xa <- axisTicks(pu[1:2], log = FALSE))) # x axis aX(2, print(ya <- axisTicks(pu[3:4], log = FALSE))) # y axis axisTicks(pu[3:4], log = FALSE, n = 10) plot(10*(0:10), log = "y"); (pu <- par("usr")) aX(2, print(ya <- axisTicks(pu[3:4], log = TRUE))) # y axis plot(2^(0:9), log = "y"); (pu <- par("usr")) aX(2, print(ya <- axisTicks(pu[3:4], log = TRUE))) # y axis