In R graphics, what is the different between plotting characters (pch) 16 and 19?

Question

I can\'t find any documentation other than mentions of \"filled\" vs \"solid\".

library(graphics)
plot.new()
points(.48, .5, pch=19)
points(.52, .5, pch=16)
         


        

Answer 1

From Hadley's new book R for Data Science: Note that there are some seeming duplicates: 0, 15, and 22 are all squares. The difference comes from the interaction of the colour and fill aesthetics. The hollow shapes (0–14) have a border determined by colour; the solid shapes (15–18) are filled with colour; the filled shapes (21–24) have a border of colour and are filled with fill.