vegan (version 2.0-10)

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).

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.

See Also

scores, polygon, text. The function is modelled after s.label in ade4 package.

Examples

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))