p <-
ggplot(mpg, aes(cty, hwy, color = factor(cyl))) +
geom_jitter(size=3) +
labs(x = "城市道路里程/加仑",
y = "高速公路里程/加仑",
colour = "图例布局") +
theme(legend.background = element_rect(color = "red"))+
theme_bw()
![](https://www.jingege.wang/wp-content/uploads/2022/01/image-5.png)
# 快捷调整
p + theme(
legend.direction = "horizontal",legend.position = c(0.7,0.2)
)
p + theme(
legend.direction = "vertical",legend.position = c(0.7,0.2)
)
![](https://www.jingege.wang/wp-content/uploads/2022/01/image-6.png)
# 精准调整
p + guides(
color = guide_legend(
ncol = 2,
byrow = TRUE,
reverse = T))+
theme(legend.position = c(0.7,0.2)
)
# 举一反三:nrow= 也可
![](https://www.jingege.wang/wp-content/uploads/2022/01/image-7.png)