invoke.symbolmap: Plot Data Using Graphics Symbol Map

Description

Apply a graphics symbol map to a vector of data values and plot the resulting symbols.

Usage

invoke.symbolmap(map, values, x=NULL, y = NULL, ...,
                 angleref=NULL,
                 add = FALSE,
                 do.plot = TRUE, started = add && do.plot)

Value

(Invisibly) the maximum diameter of the symbols, in user coordinate units.

Arguments

map: Graphics symbol map (object of class "symbolmap").
values: Vector of data that can be mapped by the symbol map.
x,y: Coordinate vectors for the spatial locations of the symbols to be plotted.
...: Additional graphics parameters (which will be applied to the entire plot).
angleref: Optional. Reference angle, or vector of reference angles, used when plotting some of the symbols. A numeric value or vector giving angles in degrees between 0 and 360.
add: Logical value indicating whether to add the symbols to an existing plot (add=TRUE) or to initialise a new plot (add=FALSE, the default).
do.plot: Logical value indicating whether to actually perform the plotting.
started: Logical value indicating whether the plot has already been initialised.

Author

Adrian Baddeley Adrian.Baddeley@curtin.edu.au, Rolf Turner rolfturner@posteo.net and Ege Rubak rubak@math.aau.dk.

Details

A symbol map is an association between data values and graphical symbols.

This command applies the symbol map map to the data values and plots the resulting symbols at the locations given by xy.coords(x,y).

Examples

Run this code

  g <- symbolmap(range=c(-1,1),
                   shape=function(x) ifelse(x > 0, "circles", "squares"),
                   size=function(x) sqrt(ifelse(x > 0, x/pi, -x))/15,
                   bg=function(x) ifelse(x > 0, "green", "red"))
  plot(square(1), main="")
  a <- invoke.symbolmap(g, runif(10, -1, 1), runifrect(10), add=TRUE)
  a

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