I am working with the library gapminder and I have generated the following graph to show the relationship between life expentancy, continent and gdp
library(gapminder)
library(dplyr)
library(ggplot2)
df <-gapminder
ggplot(db1 %>% filter(year==2007), aes(x=pop, y=gdpPercap, color=continent))+
geom_point()+scale_size(df$lifeExp)
However, the resulting dots are all the same size and I don't know why. Can someone help me?