MinorTick: Draw aesthetic minor ticks

In EarthSystemDiagnostics/grfxtools: An R package of tools to assist with various plotting tasks

Draw aesthetic minor ticks

Description

Adds minor tick marks to an existing plot.

Usage

MinorTick(
  n = 2,
  side = 1,
  tick.ratio = 0.5,
  col = "black",
  lwd = 1,
  extend = 0,
  ...
)

Arguments

n	number of intervals in which to divide the area between major tick marks on the specified axis. Values <= 1 suppress minor tick marks.
side	an integer specifying on which axis the minor ticks are to be drawn on. The axis is denoted as follows: 1=below, 2=left, 3=above and 4=right.
tick.ratio	ratio of lengths of minor tick marks to major tick marks. The length of major tick marks is retrieved from ‘par("tcl")’.
col	color of the minor ticks.
lwd	line width for the minor ticks; defaults to 1.
extend	an integer specifying the number of minor ticks to be plotted before the first and after the last major tick mark; if larger than n, it is automatically reduced to n-1. Default is to plot no extended minor ticks. Note that since minor ticks are drawn without an extra axis line, extended minor ticks are visually only useful if you use the plot bounding box() or another means of drawing a (longer) axis line.
...	further graphical parameters passed on to axis for plotting the minor ticks, see examples.

Details

This is a modified version of the function minor.tick from the package Hmisc. Main differences are i) that minor ticks are only plotted between the positions of the existing major ticks, not additionally at the major ticks, but extending the minor ticks beyond the first and last major tick is optional using the extend parameter, ii) allowing the direct setting of the colour and the line width of the minor ticks, and iii) that minor ticks can be also drawn on axes at the top or the right-hand side of the plot. The latter, however, makes it necessary to call MinorTick twice if you want to plott minor ticks on both the x and y axes on the same plot.

Author(s)

Frank Harrell, Earl Bellinger, Viktor Horvath, Thomas Münch

Source

The original version of minor.tick is available in the Hmisc package from CRAN: <https://cran.r-project.org/web/packages/Hmisc/>

Examples

plot(1 : 10)
MinorTick(n = 1) # <- no minor ticks
MinorTick()
MinorTick(side = 2, lwd = 3)
MinorTick(n = 4, side = 3)
MinorTick(n = 6, side = 4, col = 2)

# plot extended minor ticks
x <- 2 : 9
plot(x = x, y = x, axes = FALSE, xlim = c(1, 10))
par(xaxp = c(2, 9, 7))
axis(1)
axis(2)

MinorTick(n = 3, extend = 2)
# <- looks unpleasant without a bounding box
box() # better

# optional parameters that may need to be passed on include, e.g.,
# the line parameter:
plot(1 : 10, axes = FALSE, xlab = "")

axis(2)
axis(1, line = 2)

MinorTick() # <- incorrect positioning
MinorTick(line = 2) # here we go

# you need to be careful when manually setting major tick mark locations
## Not run: 
  plot(1 : 10, xlim = c(0, 10), axes = FALSE)
  axis(1, at = seq(0.5, 9.5, 1))
  MinorTick(col = "red")
  # <- this will position the minor tick marks incorrectly, since
  # \code{MinorTick} extracts the major tick mark positions from
  # \code{xaxp} and \code{yaxp}, which are not updated by the manual setting
  # in \code{axis}

## End(Not run)
# this instead works:
plot(1 : 10, xlim = c(0, 10), axes = FALSE)
par(xaxp = c(0.5, 9.5, 9))
axis(1)
MinorTick(col = "red")

EarthSystemDiagnostics/grfxtools documentation built on Aug. 5, 2023, 1:43 p.m.