Return various types of breaks and labels for ternary color keys.
BasicKey(legend_surface, limits, brklab, show_center, center, lwd)
A data frame with numeric 'id', 'p1', 'p2', 'p3' and character column 'rgb'.
A 2 by 3 matrix of lower and upper limits for p1, p2 and p3.
Breaks and labels as returned by BreaksAndLabels
.
Should the center be marked on the legend? (logical)
Ternary coordinates of the grey-point.
A numeric scalar giving the linewidth of the legend surface polygons.
A ggtern grob.