This is either awesome or perverse.

dplyr_to_ggplot2.r

libarary(plyr)
library(dplyr)
library(ggplot2)


baseball %>%
  group_by(year)%>%
  summarise(r=sum(r)) %>%
  ggplot(., aes(year, r)) +
    geom_point()
    
# at least this doesn't work
# baseball %>%
#   group_by(year, lg)%>%
#   summarise(r=sum(r)) %>%
#   ggplot(. %>% 
#            summarise(r = sum(r)), aes(year, r)) +
#     geom_point()