map.key {maptree}R Documentation

Draw Key to accompany Map of Groups

Description

Draws legends for maps of groups of observations.

Usage

  map.key (x, y, lables=NULL, new=TRUE,  ps=par("ps"), 
      size=5, gon=10, head="", sep=1, col=NULL)

Arguments

x, y coordinates of lower left position of key in proportional units (0-1) of plot.
labels vector of labels for classes, or if NULL, then integers 1:length(col), or "1".
new if TRUE, call plot.
ps pointsize of text, par parameter.
size size in mm of shaded square symbol.
gon number of sides for polygon symbol (>8 => circle).
head text heading for key.
sep separation in mm between adjacent symbols in key. If sep=0, assume a continuous scale, use gon=4, and put lables at breaks between squares.
col vector of colors from hsv, rgb etc, or if NULL, then generated as equally spaced hues, or if "gray", then generated as gray tones.

Details

Uses ngon to draw shaded polygon symbols for key.

Value

The vector of colors supplied or generated.

Author(s)

Denis White, white.denis@epa.gov

See Also

ngon, map.groups

Examples

  data (hex.env)

  # key for examples in help(map.groups)
  # range map for American Avocet
  map.key (0.2, 0.2, lables=c("absent","present"), col="gray",
      size=3, gon=6, new=TRUE, sep=1, head="key")
  # distribution of January temperatures
  cuts <- quantile (hex.env[["jan.temp"]], probs=seq(0,1,1/5))
  map.key (0.2, 0.2, lables=as.character(round(cuts,0)), 
      col="gray", size=3, new=TRUE, sep=0, head="key")

  # key for example in help(group.tree)
  map.key (0.2, 0.2, lables=as.character(seq(6)), 
      size=3, gon=6, new=TRUE, sep=1, head="node")