R: Axis brackets instead of axis ticks and lines

brackets_horizontal {lemon} | R Documentation

## Axis brackets instead of axis ticks and lines

### Description

To be used with `coord_flex_cart`, `coord_capped_cart`, etc. for displaying brackets instead of the axis ticks and lines.

### Usage

    brackets_horizontal(direction = c("up", "down"), length = unit(0.05, "npc"),
      tick.length = waiver())

    brackets_vertical(direction = c("left", "right"), length = unit(0.05,
      "npc"), tick.length = waiver())

### Arguments

`direction` | Which way should the opening side of the brackets point? up, down, left, or right?
`length` | Length of the unit, parallel with axis line.
`tick.length` | Height (width) of x-axis (y-axis) bracket. If `waiver()` (default), use `axis.ticks.length` from `theme`.

### Details

The looks of the brackets are taken from `theme(axis.ticks)`, or `theme(axis.ticks.x)` and `theme(axis.ticks.y)`, respectively.

It does not re-calculate tick marks, but lets `scale_x_*` and `scale_y_*` calculate and draw ticks and labels, and then modifies the ticks with brackets.

Both `length` and `tick.length` accepts a numeric scalar instead of a `unit` object that is interpreted as an `"npc"` unit.

### See Also

`unit`

### Examples

    library(ggplot2)
    p <- ggplot(mpg, aes(as.factor(cyl), hwy, colour=class)) +
      geom_point(position=position_jitter(width=0.3)) +
      theme_bw() +
      theme(panel.border = element_blank(), axis.line = element_line())
    p

    p <- p + coord_flex_cart(bottom=brackets_horizontal(length=unit(0.08, 'npc')))
    p
    # However getting the correct width is a matter of tweaking either length or
    # position_jitter...

    # A further adjustment,
    p + theme(panel.grid.major.x = element_blank())

[Package lemon version 0.3.3 Index]