R: Continuous colour bar guide.

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 tha 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 gudie).
`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`
`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 specify the order of this guide in the multiple guides. 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 syntax sugar for guide=guide_legend() - but the second form allows you to specify more options. As for how to specify the guide for each scales, see guides.

Value

A guide object

Examples

library(reshape2) # for melt
df <- 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 1.0.1 Index]