Function to create a color key

Source: R/pie.r

Function to create a color key

colorkey(x0, y0, x1, y1, cols = c("white", "steelblue"),
  tick.range = c(0, 1), tick.marks = seq(tick.range[1], tick.range[2],
  length.out = 5L), label.from = NULL, label.to = NULL,
  nlevels = 100, main = NULL, relative = TRUE, tick.args = list(),
  label.args = list(), main.args = list())

Arguments

x0, x1, y0, y1

Numeric scalars. Coordinates of the lower left and upper right points where the color key will be drawn as proportion of the plotting region.
cols

Character scalar. Colors specifications to create the color palette.
tick.range, tick.marks

Numeric vectors specifying the range and the tickmarks respectively.
label.from, label.to

Character scalar. Labels of the lower and upper values of the color key.
nlevels

Integer scalar. Number of levels to extrapolate.
main

Character scalar. Title of the colorkey.
relative

Logical scalar. When TRUE the color key is drawn relative to the plotting region area taking x0, x1, y0, y1 as relative location.
tick.args, label.args, main.args

Lists of arguments passed to graphics::text for drawing ticks, labels and main respectively.