adeg.panel.values: Panel function drawing a third variable into a...
In adegraphics: An S4 Lattice-Based Package for the Representation of Multivariate Data

Description Usage Arguments Value Note Author(s) References Examples

Panel function for drawing coordinates with variable representation. The values can be represented through symbols with proportional size or various colors.

1 2	adeg.panel.values(x, y, z, method, symbol, ppoints, breaks, centerpar = NULL, center = 0)

`x`	a numeric vector, x-coordinates for the symbols
`y`	a numeric vector, y-coordinates for the symbols
`z`	a numeric vector, the third variable with one value per coordinates (x, y)
`method`	a character string equal to `color` or `size`. If `color`, a palette of color is used for the symbols (one color per interval defined by `breaks`). If `size`, symbols' area is proportional to the value. Area is 0 for values equals to `center`. Two colors are used, one for values smaller than center and the other for values larger than center.
`symbol`	a character string equal to `square` or `circle`.
`ppoints`	a list of parameters as an extract of `adegpar("ppoints")`, used for points' drawing. `alpha`: transparency of points `cex`: size of points `col`: border color of points `pch`: symbol to use `fill`: filling color
`breaks`	a vector, the breaks used for splitting `z` if `method` is `color`
`centerpar`	a list to represent center value using elements in the `adegpar("ppoints")` list or `NULL` value. If the method is `size`, z-values equals to `center` have a size of zero. If `centerpar` is not `NULL`, those z-values are shown as points with the `centerpar` drawing parameters.
`center`	a center value for method `size`

Draws the points.

For more information about the use of panel functions, please see the lattice package developed by Deepayan Sarkar.

For the symbols size, the method is size uses perceptual scaling (Tanimura et al. 2006).

Alice Julien-Laferriere, Aurelie Siberchicot aurelie.siberchicot@univ-lyon1.fr and Stephane Dray

Tanimura, S. and Kuroiwa, C. and Mizota, T. 2006 Proportional symbol mapping in R Journal of Statistical Software 15, 1–7

if(require(lattice, quiet = TRUE)) {
param <- adegpar("ppoints")[[1]]
param$col <- adegpar("ppalette")[[1L]]$quanti(2)
z <- rnorm(10)
xyplot(1:10 ~ 1:10, panel = function(x, y, ...){
  adeg.panel.values(x, y, z, method = "size", symbol = "square", ppoints =
  param, breaks = pretty(z, 4))})

param$col <- adegpar()$ppalette$quali((length(pretty(z, 2)) - 1))
xyplot(1:10 ~ 1:10, panel = function(x, y, ...){
  adeg.panel.values(x, y, z, method = "color", symbol = "circle", 
                    ppoints = param, breaks = pretty(z, 2))}) 
}