day4-R语言基础

> 1+2
[1] 3
> 3-2
[1] 1
> 2*3
[1] 6
> 6/3
[1] 2

> X <- 1+2
> X
[1] 3

> rm(X)
> x
Error: object 'x' not found
> X
Error: object 'X' not found

history() 

library(tidyverse)
p <- mpg #将内置数据框数据赋值给p
library(dplyr)
distinct(p,manufacturer) #manufacturer替换为其他列名。仅显示非重复值，不显示重复次数。
count(p,manufacturer) #显示出现次数
# 基础组图
ggplot(data = mpg) + 
       geom_point(mapping = aes(x = displ, y = hwy))
#设置颜色/大小
ggplot(data = mpg) + 
  geom_point(mapping = aes(x = displ, y = hwy, color = class))#size = class
# 将车型class映射给透明度
ggplot(data = mpg) + 
  geom_point(mapping = aes(x = displ, y = hwy, alpha = class))
# 将车型class映射给形状
ggplot(data = mpg) + 
  geom_point(mapping = aes(x = displ, y = hwy, shape = class))
#手动设置颜色
 gplot(data = mpg) + 
  geom_point(mapping = aes(x = displ, y = hwy), color = "blue")
#手动设置形状
ggplot(data = mpg) + 
      geom_point(mapping = aes(x = displ, y = hwy, stroke = 3),shape=21)
#分面
ggplot(data = mpg) + 
  geom_point(mapping = aes(x = displ, y = hwy)) + 
  facet_wrap(~ class, nrow = 2) #分两行展示
gplot(data = mpg) + 
  geom_point(mapping = aes(x = displ, y = hwy)) + 
  facet_grid(drv ~ cyl)
ggplot(data = mpg) + 
  geom_point(mapping = aes(x = displ, y = hwy)) + 
  facet_grid(. ~ cyl)

ggplot(data = mpg) +
  geom_smooth(mapping = aes(x = displ, y = hwy, group = drv))
  #隐式分组-线型
ggplot(data = mpg) +
  geom_smooth(
    mapping = aes(x = displ, y = hwy, linetype = drv),
  )
#隐式分组-颜色
ggplot(data = mpg) +
  geom_smooth(
    mapping = aes(x = displ, y = hwy, color = drv),
    show.legend = FALSE  #不显示图例
  )