axis.break {plotrix}

Place a "break" mark on an axis

Description

Places a "break" mark on an axis on an existing plot.

Usage

 axis.break(axis=1,breakpos=NULL,pos=NULL,bgcol="white",breakcol="black",
  style="slash",brw=0.02)

Arguments

axis

which axis to break

breakpos

where to place the break in user units

pos

position of the axis (see axis).

bgcol

the color of the plot background

breakcol

the color of the "break" marker

style

Either ‘⁠gap⁠’, ‘⁠slash⁠’ or ‘⁠zigzag⁠’

brw

break width relative to plot width

Details

The ‘⁠pos⁠’ argument is not needed unless the user has specified a different position from the default for the axis to be broken.

Value

nil

Note

There is some controversy about the propriety of using discontinuous coordinates for plotting, and thus axis breaks. Discontinuous coordinates allow widely separated groups of values or outliers to appear without devoting too much of the plot to empty space. The major objection seems to be that the reader will be misled by assuming continuous coordinates. The ‘⁠gap⁠’ style that clearly separates the two sections of the plot is probably best for avoiding this.

Author(s)

Jim Lemon and Ben Bolker

See Also

gap.plot

Examples

 plot(3:10, main = "Axis break test")
 # put a break at the default axis and position
 axis.break()
 axis.break(2, 2.9, style = "zigzag")
 twogrp <- c(rnorm(10) + 4, rnorm(10) + 20)
 gap.plot(twogrp,gap = c(8,16), xlab = "Index", ylab = "Group values",
  main = "Two separated groups with gap axis break",
  col = c(rep(2, 10), rep(3, 10)), ytics = c(3, 5, 18, 20))
 legend(12, 6, c("Low group", "High group"), pch = 1, col = 2:3)