第一章 数据探索

author: "Yuyuan Zhang"
date: "2021/2/6"

library(ggplot2)
library(ggpubr)

1点图-----

qplot(mtcars$wt,mtcars$mpg)
qplot(wt,mpg,data = mtcars)
ggplot(mtcars,aes(wt,mpg))+geom_point()
dev.off()

2折线图----

plot(pressure$temperature,pressure$pressure,type = "l")
points(pressure$temperature,pressure$pressure)

lines(pressure$temperature,pressure$pressure/2,col="red")
points(pressure$temperature,pressure$pressure/2,col="red")
dev.off()
#
qplot(pressure$temperature,pressure$pressure,geom = "line")
#等价于下面命令
ggplot(pressure,aes(temperature,pressure))+geom_line()
#添加点
qplot(pressure$temperature,pressure$pressure,geom = c("line","point"))
ggplot(pressure,aes(temperature,pressure))+geom_point()+geom_line()

3条图

table(mtcars$cyl)
barplot(table(mtcars$cyl))
str(BOD)
qplot(factor(BOD$Time),BOD$demand,geom = "bar")#绘制不出来
qplot(Time,demand,data = BOD,geom = "bar",stat = "identity")#绘制不出来
ggplot(BOD,aes(Time,demand))+geom_bar(stat = "identity")
qplot(mtcars$cyl)
qplot(factor(mtcars$cyl))

4绘制直方图

quantile(mtcars$mpg)
hist(mtcars$mpg)
hist(mtcars$mpg,breaks = 10)
qplot(mtcars$mpg,binwidth=4)
ggplot(mtcars,aes(mpg))+geom_histogram(binwidth = 4)
dev.off()

5绘制箱线图

plot(ToothGrowth$supp,ToothGrowth$len)
boxplot(len~supp,data = ToothGrowth)
boxplot(len~supp+dose,data = ToothGrowth)

qplot(ToothGrowth$supp,ToothGrowth$len,geom = "boxplot")
ggplot(ToothGrowth,aes(supp,len))+geom_boxplot()
#使用interaction组合变量
qplot(interaction(ToothGrowth$supp,ToothGrowth$dose),ToothGrowth$len,geom = "boxplot")
ggplot(ToothGrowth,aes(interaction(supp,dose),len))+geom_boxplot()

6绘制函数图像-----

curve(x^3-5*x,from = -4,to=4)
myfun <- function(xvar){
  1/(1+exp(-xvar+10))
}
curve(myfun(x),from = 0,to=20)
curve(1-myfun(x),add = T,col="red")