crucial graphics subfunction
OPC_Legend(
binColors = c(1:8),
binNumber = 8,
maskDiscard = F,
textCol = "black",
size = 1,
lineCol = "black"
)
number sequence for bins and their colors
numeric number of different bins
logical determining whether faces will be blacked out because they are discarded
color for the text in the circle legend
scaling factor for the legend size
color for the lines in the legend OPC_Legend()