R: Add a legend to a density strip or shaded region

denstrip.legend {denstrip}

R Documentation

Add a legend to a density strip or shaded region

Description

Add a legend to an existing plot with a density strip or shaded region, indicating the mapping of colours to densities.

Usage

denstrip.legend(x, y, width, len, colmax, colmin="white", gamma=1,
                horiz=FALSE, max=1, nticks = 5, ticks, value.adj = 0,
                cex, main = "Density", lattice=FALSE)
panel.denstrip.legend(...)

Arguments

`x`	Central x position of the legend.
`y`	Central y position of the legend.
`width`	Width of the legend strip, that is, the length of its shorter dimension. Defaults to 1/30 of the axis range.
`len`	Length of the legend strip, that is, the length of its longer dimension. Defaults to 1/4 of the axis range.
`colmax`	Colour at the maximum density, either as a built-in R colour name (one of `colors()`) or an RGB hex value. Defaults to `par("fg")` or its lattice equivalent, which is `"black"` by default.
`colmin`	Colour to shade the minimum density, likewise. Defaults to "white". If this is set to `"transparent"`, and the current graphics device supports transparency (see `rgb`), then overlapping strips will merge smoothly.
`gamma`	Gamma correction to apply to the colour palette, see `denstrip`.
`horiz`	Legend strip drawn vertically (`FALSE`) or horizontally (`TRUE`).
`max`	Maximum density on the legend, which is represented by `colmax`. With the default of 1, the legend indicates the mapping of colours to proportions of the maximum density.
`nticks`	Number of tick marks on the axis adjacent to the legend, if `ticks` not supplied.
`ticks`	Positions of numbered ticks on the axis adjacent to the legend. Defaults to `nticks` equally spaced ticks between 0 and the maximum density.
`value.adj`	Extra adjustment for the axis labels to the right (if `horiz=FALSE`) or downwards (if `horiz=TRUE`).
`cex`	Text expansion. Defaults to `par("cex") * 0.75` or `trellis.par.get("axis.text")$cex * 0.75`.
`main`	Text to place above the legend.
`lattice`	Set this to `TRUE` to make `denstrip.legend` a lattice panel function instead of a base graphics function. `panel.denstrip.legend(x,...)` is equivalent to `denstrip.legend(x, lattice=TRUE, ...)`.
`...`	Other arguments passed to `panel.denstrip.legend`.

Author(s)

Christopher Jackson <chris.jackson@mrc-bsu.cam.ac.uk>

Examples


if (requireNamespace("survival", quietly=TRUE)){

library(survival)
fit <- survfit(Surv(time, status) ~ 1, data=aml, conf.type="log-log")
plot(fit, col=0)
densregion(fit)
denstrip.legend(100, 0.8)

    ### TODO if max not supplied - ticks are not meaningful.
    ### In help example, find actual max dens used for densregion

denstrip.legend(120, 0.8, width=3, len=0.4, value.adj=5)
denstrip.legend(40, 0.9, horiz=TRUE)
denstrip.legend(60, 0.7, horiz=TRUE, width=0.02, len=50, value.adj=0.04)


}