color_mapping_legend-ColorMapping-method: Draw legend based on color mapping
In eilslabs/ComplexHeatmap: Making Complex Heatmaps

Description Usage Arguments Details Value Author(s) Examples

Draw legend based on color mapping

## S4 method for signature 'ColorMapping'
color_mapping_legend(object, ...,
    plot = TRUE,
    title = object@name,
    title_gp = gpar(fontsize = 10, fontface = "bold"),
    title_position = c("topleft", "topcenter", "leftcenter", "lefttop"),
    color_bar = object@type,
    grid_height = unit(4, "mm"),
    grid_width = unit(4, "mm"),
    border = NULL,
    at = object@levels,
    labels = at,
    labels_gp = gpar(fontsize = 10),
    nrow = NULL,
    ncol = 1,
    legend_height = NULL, legend_width = NULL,
    legend_direction = c("vertical", "horizontal"),
    param = NULL)

`object`	a `ColorMapping-class` object.
`plot`	whether to plot or just return the size of the legend viewport.
`title`	title of the legend, by default it is the name of the legend
`title_gp`	graphical parameters for legend title
`title_position`	position of the title
`color_bar`	a string of "continous" or "discrete". If the mapping is continuous, whether show the legend as discrete color bar or continuous color bar
`grid_height`	height of each legend grid.
`grid_width`	width of each legend grid.
`border`	color for legend grid borders.
`at`	break values of the legend
`labels`	labels corresponding to break values
`labels_gp`	graphcial parameters for legend labels
`nrow`	if there are too many legend grids, they can be put as an array, this controls number of rows
`ncol`	if there are too many legend grids, they can be put as an array, this controls number of columns
`legend_height`	height of the legend, only works when `color_bar` is `continuous` and `direction` is `vertical`
`legend_width`	width of the legend, only works when `color_bar` is `continuous` and `direction` is `horizontal`
`legend_direction`	when `color_bar` is `continuous`, should the legend be vertical or horizontal?
`param`	will be parsed if the parameters are specified as a list
`...`	pass to `viewport`.

A viewport is created which contains a legend title, legend grids and corresponding labels.

This function will be improved in the future to support more types of legends.

A grob object which contains the legend

Zuguang Gu <z.gu@dkfz.de>

# discrete color mapping for characters
cm = ColorMapping(name = "test",
    colors = c("blue", "white", "red"),
    levels = c("a", "b", "c"))
grid.newpage()
color_mapping_legend(cm)

# discrete color mapping for numeric values
cm = ColorMapping(name = "test",
    colors = c("blue", "white", "red"),
    levels = c(1, 2, 3))
grid.newpage()
color_mapping_legend(cm)

# continuous color mapping
require(circlize)
cm = ColorMapping(name = "test",
    col_fun = colorRamp2(c(0, 0.5, 1), c("blue", "white", "red")))
grid.newpage()
color_mapping_legend(cm, title_gp = gpar(fontsize = 16))