linkmap {iL04}R Documentation

Plot a set of links on a topographic map

Description

Small differences are represented as dark lines on a topographic map.

Usage

linkmap(coo, dst, labels = "dots", cex = 1, limit = .25,
        shift = .2, separate = 10, asp = NA, nmax = NA, map = NULL,
        xlab = NULL, ylab = NULL, col = gray(0:40/40), ...)

Arguments

coo a dataframe with x- and y-coordinates of locations stored in the first two columns, and names of locations stored as rownames.
dst a dissimilarity structure as produced by the dist function, with names stored in the attribute "Labels".
labels what to use as labels. This is either a word: one of "none" (no labels), "names" (use rownames of argument coo), or "dots" (use dots); or a vector of labels ordered in accordance with the data in argument coo.
cex the size of the labels relative to the default text size.
limit only plot lines not longer than limit times the length of the longest line. Results may not be correct if asp is not set.
shift contrast enhancement. A value between 0 and 1. A smaller value results in fewer visible lines.
separate contrast enhancement. Some positive value. A value of 1 will result in a gradual transition from light lines to dark lines, a value of 50 will result in a sharp separation of light and dark lines.
asp the aspect ratio. See plot.window function.
nmax maximum number of lines to draw. The actual number of lines drawn may be less than this number if limit is less than 1.
map an optional two-column matrix with a set of line segments, used to draw a map. See lines for the use of NA values.
xlab a title for the x axis.
ylab a title for the y axis.
col a colour palette to use for the lines, from dark to light.
... further arguments to the plot function.

Value

None.

References

RuG/L04 - software for dialectometrics and cartography: http://www.let.rug.nl/~kleiweg/L04/

See Also

cccmap, clustermap, mdsmap, mean.asp

Examples

data(PA)
data(PA.coo)
data(PA.map)
asp <- mean.asp(PA.map[, 2])
linkmap(PA.coo[, 1:2], PA, labels = PA.coo$idx,
        main = "Pennsylvania, USA",
        nmax = 600, limit = .2, separate = 20, asp = asp, map = PA.map)

[Package iL04 version 1.15 Index]