R语言_ggplot2_Lv2_Legend

R语言_学习笔记

• 设置图例的标题

> p1 <- ggplot(PlantGrowth,aes(group,weight)) + geom_boxplot(aes(fill=group))
> p1 + labs(fill="Condition")  
#设置图例标题的方法有很多，个人认为这种方式最好！

• 移除图例

(1)、只移除某一个图例：

> p1 + guides(fill=FALSE) 

(2)、移除全部图例：

> p1 + theme(legend.position="none") 

• 修改图例标签

> p1 + labs(fill="Condition") + scale_fill_discrete(labels=c("Control","Condition 1","Condition 2")) + theme(legend.text=element_text(face="bold.italic",color="olivedrab4",size=12))

• 处理多行文本标签的叠加问题

p4 <- p1 + labs(fill="Condition") + scale_fill_discrete(labels=c("Control","Type 1\ntreatment","Type2\ntreatment")) + theme(legend.text=element_text(face="bold.italic",color="olivedrab4",size=13))
p4

library(grid)
p4 + theme(legend.text=element_text(lineheight=0.8),
           legend.key.height=unit(1,"cm"))