## sex weight
## 1 F 49
## 2 F 56
## 3 F 60
## 4 F 43
## 5 F 57
## 6 F 58
ggplot(df2, aes(x=weight)) + geom_histogram(binwidth=1)
3.2 Add mean line on a histogram plot
ggplot(df2, aes(x=weight)) +
geom_histogram(binwidth=1, color="black", fill="white") +
geom_vline(aes(xintercept=mean(weight)),color="black", linetype="dashed", size=0.5)
3.3 Change histogram plot fill colors
#Use the plyr package to calculate the average weight of each group :
mu <- ddply(df2, "sex", summarise, grp.mean=mean(weight))
head(mu)
## sex grp.mean
## 1 F 54.70
## 2 M 65.36
#draw the plot
ggplot(df2, aes(x=weight, color=sex)) +
geom_histogram(binwidth=1, fill="white", position="dodge")+
geom_vline(data=mu, aes(xintercept=grp.mean, color=sex), linetype="dashed") +
scale_color_brewer(palette="Paired") +
theme_classic()+
theme(legend.position="top")
