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Build a paired-palette legend (split-tile glyph + gradient bars)

Source: R/legend.R
bi_legend.Rd

Creates a standalone legend explaining a biheat() plot: two horizontal gradient bars (upper and lower triangle palettes) and a small split-tile glyph whose callouts carry upper_name and lower_name alongside the side each one is drawn on. Returns a grob you can draw with grid::grid.draw() or compose into another plot.

Usage

bi_legend(
  upper_name = "A",
  lower_name = "B",
  upper_palette = c("white", "red"),
  lower_palette = c("white", "blue"),
  upper_range = c(0, 1),
  lower_range = c(0, 1),
  split = c("down", "up")
)

Arguments

upper_name, lower_name

Labels for the two sides.

upper_palette, lower_palette

Colour vectors interpolated across each side.

upper_range, lower_range

Numeric length-2 vectors. Tick labels are drawn at the endpoints and midpoint. Default c(0, 1).

split

"down" or "up" — diagonal direction in the glyph.

Value

A bi_legend object (a grid grob).

Details

Inside a biheat() / plot.clutch() call, the same legend is drawn automatically next to the panel. Use this function when you want the legend as a standalone graphic (e.g. for a paper figure where the panel is built separately).

Examples

g <- bi_legend("A", "B")
grid::grid.newpage()
grid::grid.draw(g)