mizmay

#negative numbers for "symbol" will be interpreted as Unicode values.
#But you must use a fint that supprots the symbols you want.

dataset <- chain(1:16, expand.grid(x=., y=.), mutate(shape=seq_along(x)))

print(ggplot(dataset) + aes(x=x, y=y, shape=factor(shape))
 + geom_point()
 + discrete_scale("shape", "manual", name="shape", palette=function(x) -seq(0x25A0L, length=x))
 + theme(legend.position="none")
 )