guide_colourbar {ggplot2} | R Documentation

## Continuous colour bar guide.

### Description

Colour bar guide shows continuous color scales mapped onto values. Colour bar is available with `scale_fill` and `scale_colour`. For more information, see the inspiration for this function: Matlab's colorbar function.

### Usage

    guide_colourbar(title = waiver(), title.position = NULL,
      title.theme = NULL, title.hjust = NULL, title.vjust = NULL,
      label = TRUE, label.position = NULL, label.theme = NULL,
      label.hjust = NULL, label.vjust = NULL, barwidth = NULL,
      barheight = NULL, nbin = 20, raster = TRUE, ticks = TRUE,
      draw.ulim = TRUE, draw.llim = TRUE, direction = NULL,
      default.unit = "line", reverse = FALSE, order = 0, ...)

    guide_colorbar(title = waiver(), title.position = NULL,
      title.theme = NULL, title.hjust = NULL, title.vjust = NULL,
      label = TRUE, label.position = NULL, label.theme = NULL,
      label.hjust = NULL, label.vjust = NULL, barwidth = NULL,
      barheight = NULL, nbin = 20, raster = TRUE, ticks = TRUE,
      draw.ulim = TRUE, draw.llim = TRUE, direction = NULL,
      default.unit = "line", reverse = FALSE, order = 0, ...)

### Arguments

`title` | A character string or expression indicating a title of guide. If `NULL`, the title is not shown. By default (`waiver`), the name of the scale object or the name specified in `labs` is used for the title.
`title.position` | A character string indicating the position of a title. One of "top" (default for a vertical guide), "bottom", "left" (default for a horizontal guide), or "right."
`title.theme` | A theme object for rendering the title text. Usually the object of `element_text` is expected. By default, the theme is specified by `legend.title` in `theme` or theme.
`title.hjust` | A number specifying horizontal justification of the title text.
`title.vjust` | A number specifying vertical justification of the title text.
`label` | logical. If `TRUE` then the labels are drawn. If `FALSE` then the labels are invisible.
`label.position` | A character string indicating the position of a label. One of "top", "bottom" (default for horizontal guide), "left", or "right" (default for vertical guide).
`label.theme` | A theme object for rendering the label text. Usually the object of `element_text` is expected. By default, the theme is specified by `legend.text` in `theme` or theme.
`label.hjust` | A numeric specifying horizontal justification of the label text.
`label.vjust` | A numeric specifying vertical justification of the label text.
`barwidth` | A numeric or a `unit` object specifying the width of the colorbar. Default value is `legend.key.width` or `legend.key.size` in `theme` or theme.
`barheight` | A numeric or a `unit` object specifying the height of the colorbar. Default value is `legend.key.height` or `legend.key.size` in `theme` or theme.
`nbin` | A numeric specifying the number of bins for drawing colorbar. A smoother colorbar for a larger value.
`raster` | A logical. If `TRUE` then the colorbar is rendered as a raster object. If `FALSE` then the colorbar is rendered as a set of rectangles. Note that not all graphics devices are capable of rendering raster image.
`ticks` | A logical specifying if tick marks on colorbar should be visible.
`draw.ulim` | A logical specifying if the upper limit tick marks should be visible.
`draw.llim` | A logical specifying if the lower limit tick marks should be visible.
`direction` | A character string indicating the direction of the guide. One of "horizontal" or "vertical."
`default.unit` | A character string indicating `unit` for `barwidth` and `barheight`.
`reverse` | logical. If `TRUE` the colorbar is reversed. By default, the highest value is on the top and the lowest value is on the bottom
`order` | positive integer less that 99 that specifies the order of this guide among multiple guides. This controls the order in which multiple guides are displayed, not the contents of the guide itself. If 0 (default), the order is determined by a secret algorithm.
`...` | ignored.

### Details

Guides can be specified in each `scale_*` or in `guides`. `guide="legend"` in `scale_*` is syntactic sugar for `guide=guide_legend()` (e.g. `scale_color_manual(guide = "legend")`). As for how to specify the guide for each scale in more detail, see `guides`.

### Value

A guide object

### See Also

Other guides: `guide_legend`, `guides`

### Examples

    df <- reshape2::melt(outer(1:4, 1:4), varnames = c("X1", "X2"))

    p1 <- ggplot(df, aes(X1, X2)) + geom_tile(aes(fill = value))
    p2 <- p1 + geom_point(aes(size = value))

    # Basic form
    p1 + scale_fill_continuous(guide = "colorbar")
    p1 + scale_fill_continuous(guide = guide_colorbar())
    p1 + guides(fill = guide_colorbar())

    # Control styles

    # bar size
    p1 + guides(fill = guide_colorbar(barwidth = 0.5, barheight = 10))

    # no label
    p1 + guides(fill = guide_colorbar(label = FALSE))

    # no tick marks
    p1 + guides(fill = guide_colorbar(ticks = FALSE))

    # label position
    p1 + guides(fill = guide_colorbar(label.position = "left"))

    # label theme
    p1 + guides(fill = guide_colorbar(label.theme = element_text(colour = "blue", angle = 0)))

    # small number of bins
    p1 + guides(fill = guide_colorbar(nbin = 3))

    # large number of bins
    p1 + guides(fill = guide_colorbar(nbin = 100))

    # make top- and bottom-most ticks invisible
    p1 + scale_fill_continuous(limits = c(0,20), breaks=c(0, 5, 10, 15, 20),
     guide = guide_colorbar(nbin=100, draw.ulim = FALSE, draw.llim = FALSE))

    # guides can be controlled independently
    p2 +
      scale_fill_continuous(guide = "colorbar") +
      scale_size(guide = "legend")
    p2 + guides(fill = "colorbar", size = "legend")

    p2 +
      scale_fill_continuous(guide = guide_colorbar(direction = "horizontal")) +
      scale_size(guide = guide_legend(direction = "vertical"))

[Package ggplot2 version 2.1.0 Index]