R: Produce a legend for continuous gradient scales

SpectrumLegend {TreeTools} | R Documentation

## Produce a legend for continuous gradient scales

### Description

Prints an annotated vertical bar coloured according to a continuous palette.

### Usage

    SpectrumLegend(
      x0 = 0.05,
      y0 = 0.05,
      x1 = x0,
      y1 = y0 + 0.2,
      absolute = FALSE,
      legend = character(0),
      palette,
      lwd = 4,
      lty = 1,
      lend = "square",
      pos = 4,
      ...
    )

### Arguments

`x0, y0, x1, y1` | Coordinates of the bottom-left and top-right end of the bar.
`absolute` | Logical specifying whether `x` and `y` values denote coordinates (`TRUE`) or relative position, where (0, 0) denotes the bottom-left of the plot area and (1, 1) the top right.
`legend` | Character vector with which to label points on `palette`.
`palette` | Colour palette to depict.
`lwd, lty, lend` | Additional parameters to `segments()`, controlling line style.
`pos, ...` | Additional parameters to `text()`.

### Details

This convenience function is not yet very customizable; do file a GitHub issue if you would value additional functionality.

### Author(s)

Martin R. Smith (martin.smith@durham.ac.uk)

### Examples

    plot(0:1, 0:1, type = "n", frame.plot = FALSE,
         xlab = "x", ylab = "y")
    SpectrumLegend(legend = c("Dark", "Middle", "Bright"),
                   palette = hcl.colors(32L), lwd = 5)
    SpectrumLegend(0.4, 0.95, 0.9, 0.95, abs = TRUE,
                   legend = seq(1, 9, by = 2), palette = 1:9, pos = 1)

[Package TreeTools version 1.7.2 Index]