If and how arrows indicating receptor vectors should be drawn.
Options are "relative" (default), "absolute" or "none". See
description.
achro
Logical. Should the achromatic variable be plotted as a
dimension? (only available for dichromats and trichromats, defaults to
FALSE).
arrow.labels
Logical. Should labels be plotted for receptor arrows?
(defaults to TRUE)
arrow.col
color of the arrows and labels.
arrow.p
scaling factor for arrows.
labels.cex
size of the arrow labels.
margin
accepts either "recommended", where the function will choose
margin attributes, or a numerical vector of the form c(bottom, left, top, right) which gives the number of lines of margin to be specified on the
four sides of the plot. (Default varies depending on plot dimensionality).
square
logical. Should the aspect ratio of the plot be held to 1:1?
(defaults to TRUE).