Let\'s say I have a lot of values around 0,1 and a few around 10. I have mapped them i.e., with:
geom_point(aes(size=value))
..which gives
If you look in ?scale_size you'll see range argument:
?scale_size
range
df <- data.frame(x = 1:10,y = runif(10),sz = c(rep(1,8),10,10)) ggplot(df,aes(x = x,y = y,size = sz)) + geom_point() + scale_size_continuous(range = c(2,4))