ggplot(aushealth, aes(x=condition, y=Population, fill=year)) +
+ geom_bar(stat="identity", position=position_dodge())
盼望岁月并肩,却又重逢。
Condition Year Population
Asthma 2001 10.0
Asthma 2017 13.1
Back Issue 2001 7.5
Back Issue 2017 6.3
我究竟做错了什么?