ggplot2 geom函数第一讲geom_abline、geom_hline、geom_bar和geom_col

参考https://ggplot2.tidyverse.org/reference/

1.geom_abline和geom_hline

ggplot(mtcars) +
  geom_point(aes(mpg, disp, colour = gear)) +
  theme_bw()+
  geom_hline(yintercept = c(300, 400), colour = 'red', linetype = 2, size = 2) +
  geom_vline(xintercept = c(20, 25), colour = 'blue', linetype = 3, size = 3)

image.png

2.geom_bar和geom_col

2.1 count or weight 数量或权重

g <- ggplot(mpg, aes(class))
g + geom_bar() #count
g + geom_bar(aes(weight = displ)) #weight

count

weight

2.2 方向，把数据赋值给y，则转为横向

ggplot(mpg) + geom_bar(aes(y = class))

横向

2.3 position

p <- ggplot(data = diamonds, mapping = aes(x = cut, fill = clarity))

#default position stack
p + geom_bar() 

#identity由于遮挡问题不适合做bar图
p + geom_bar(position = "identity") 

p + geom_bar(position = "identity", fill = NA, aes(colour = clarity))

p + geom_bar(position = "fill")

p + geom_bar(position = "dodge")

stack

identity

identity透明

fill

dodge