ordilabel: Add Text on Non-transparent Label to an Ordination Plot.

Description

Function ordilabel is similar to text, but the text is on an opaque label. This can help in crowded ordination plots: you still cannot see all text labels, but at least the uppermost are readable. Argument priority helps to make the most important labels visible.

Usage

ordilabel(x, display, labels, choices = c(1, 2), priority, select, 
    cex = 0.8, fill = "white", border = NULL, col = NULL, xpd = TRUE, ...)

Arguments

x: An ordination object an any object known to scores.
display: Kind of scores displayed (passed to scores).
labels: Optional text used in plots. If this is not given, the text is found from the ordination object.
choices: Axes shown (passed to scores).
priority: Vector of the same length as the number of labels. The items with high priority will be plotted uppermost.
select: Items to be displayed. This can either be a logical vector which is TRUE for displayed items or a vector of indices of displayed items.
cex: Character expansion for the text (passed to text).
fill: Background colour of the labels (the col argument of polygon).
border: The colour and visibility of the border of the label as defined in polygon.
col: Text colour. Default NULL will give the value of border or par("fg") if border is NULL.
xpd: Draw labels also outside the plot region (see par).
...: Other arguments (passed to text).

Author

Jari Oksanen

Details

The function may be useful with crowded ordination plots, in particular together with argument priority. You will not see all text labels, but at least some are readable. Other alternatives to crowded plots are identify.ordiplot, orditorp and orditkplot.

Examples

Run this code

data(dune)
ord <- cca(dune)
plot(ord, type = "n")
ordilabel(ord, dis="sites", cex=1.2, font=3, fill="hotpink", col="blue")
## You may prefer separate plots, but here species as well
ordilabel(ord, dis="sp", font=2, priority=colSums(dune))