R: Add a color key to a plot

hkey {squash} | R Documentation

## Add a color key to a plot

### Description

Add a horizontal or vertical color key to a plot

### Usage

    hkey(map, title = NA, side = 1, stretch = 1.4, x, y, skip, wh)
    vkey(map, title = NA, side = 2, stretch = 1.4, x, y, skip, wh)

### Arguments

`map` | A list, as generated by `makecmap`.
`title` | Title for the key.
`side` | Where to place the labels. (1 or 3 for `hkey`, 2 or 4 for `vkey`)
`stretch` | Aspect ratio of the color rectangles.
`x, y` | Position of lower left corner of the color rectangles. If missing, the key will be placed automatically in the lower-left (`hkey`) or lower-right (`vkey`) corner of the figure region.
`skip` | Omit every `skip` labels (optional).
`wh` | Integer indices indicating which labels to include (optional).

### Details

This functions tries to label as many breakpoints as possible, but if the labels would overlap a subset of labels is chosen automatically. If this doesn't look right, the subset of labels can be specified with either `skip` or `wh`.

Clipping is turned off, so the key can be placed anywhere in the figure region, including the margins.

### Examples

      attach(iris)
      map <- makecmap(Petal.Length)
      pl.color <- cmap(Petal.Length, map = map)

      plot(Sepal.Length, Sepal.Width, col = pl.color, pch = 16)
      hkey(map, title = 'Petal length (hkey default)')
      hkey(map, title = 'Another hkey', x = 3.8, y = 4.7, stretch = 3)

      ## looks bad with default margins
      vkey(map, title = 'vkey default')

      vkey(map, title = 'Small vkey', x = 7.8, y = 4, stretch = 0.3)

[Package squash version 1.0.8 Index]