1. 散点图

library(ggplot2)
library(tidyverse)
library(cowplot)
#准备数据
set.seed(1000)
small_diamonds<-sample_n(diamonds,size=500)
dim(small_diamonds)

colnames(small_diamonds)
 [1] "carat"   "cut"     "color"   "clarity" "depth"   "table"   "price"   "x"       "y"       "z"      

ggplot(data=small_diamonds,aes(x=carat,y=price))+
  geom_point(shape=21,size=4,aes(fill= cut))+geom_smooth()

#绘图，加拟合曲线，其中method=lm 加拟合直线，不加method的画默认是拟合曲线
p1<-ggplot(data=small_diamonds,aes(x=carat,y=price))+
  geom_point(shape=21,size=4,aes(fill= cut))+geom_smooth(method = "lm")


#去掉拟合曲线的置信区间 se=F
p2<-ggplot(data=small_diamonds,aes(x=carat,y=price))+
  geom_point(shape=21,size=4,aes(fill= cut))+geom_smooth(method = "lm",se=F)

#不同分组都画拟合曲线 aes(group=cut,color=cut),
p3<-ggplot(data=small_diamonds,aes(x=carat,y=price))+
  geom_point(shape=21,size=4,aes(fill= cut))+geom_smooth(aes(group=cut,color=cut),method = "lm",se=F)

plot_grid(p1,p2,p3)

image.png

计算相关性

> cor.test(small_diamonds$carat,small_diamonds$price,method = "pearson")

    Pearson's product-moment correlation

data:  small_diamonds$carat and small_diamonds$price
t = 59.696, df = 498, p-value < 2.2e-16
alternative hypothesis: true correlation is not equal to 0
95 percent confidence interval:
 0.9249769 0.9466265
sample estimates:
      cor 
0.9366908 

添加注释 annotate('text',x=2.5,y=20,label="r = 0.91; pvalue = 2.2e-16")

 ggplot(data=small_diamonds,aes(x=carat,y=price))+theme_bw()+
  geom_point(shape=21,size=4,aes(fill= cut))+geom_smooth(method = "lm",se=F)+
  annotate('text',x=2.5,y=20,label="r = 0.91; pvalue = 2.2e-16")+
  theme(legend.position = c(0.1,0.83))

image.png

添加边际图

1. 安装ggextra

install.packages("ggextra")
library(ggextra)
p3 <- ggplot(data=small_diamonds,aes(x=carat,y=price))+theme_bw()+
  geom_point(shape=21,size=4,aes(fill= cut))+geom_smooth(aes(group=cut,color=cut),method = "lm",se=F)+
  annotate('text',x=2.5,y=20,label="r = 0.91; pvalue = 2.2e-16")+
  theme(legend.position = c(0.1,0.83))

ggExtra::ggMarginal(
  p = p3,
  type = 'density',
  margins = 'both',
  size = 5,
  colour = 'black',
  fill = 'gray'

2. 选择代码块, 然后选择add in里面的 ggExtra插件

image.png
image.png

3. 添加边际图

image.png

添加地毯线

ggplot(data=small_diamonds,aes(x=carat,y=price))+theme_bw()+
  geom_point(shape=21,size=4,aes(fill= cut))+geom_smooth(aes(group=cut,color=cut),method = "lm",se=F)+
  annotate('text',x=2.5,y=20,label="r = 0.91; pvalue = 2.2e-16")+
  theme(legend.position = c(0.1,0.83))+
  geom_rug(aes(color=cut),length = unit(3,"mm"))

image.png