R云朵图：等高线图+密度图

# 数据
data <- bind_rows(
     tibble(x = rnorm(1000, mean = 10,sd = 6),
           y = rnorm(1000, mean = 12,sd = 3),group = "a"),
     tibble(x = rnorm(1000, mean = 20, sd = 8),
           y = rnorm(1000, mean = 25, sd = 2),group = "b"),
     tibble(x = rnorm(1000, mean = 30, sd = 7),
           y = rnorm(1000, mean = 33, sd = 2),group = "c"))

# 画图
  library(ggplot2)
  library(aplot)

  p1 <- ggplot(data, aes(x = x, y = y,fill=group)) +
    stat_density_2d(aes(group = ..group..), geom = "polygon",
                    colour="burlywood",size = 1,alpha=.7,linetype=2)+
    theme_classic()+guides(fill=FALSE)

  p2 <- ggplot(data,aes(x = x,fill=group))+
    geom_density(alpha=0.5)+
    scale_y_continuous(expand = c(0,0))+
    theme_minimal()+labs(y=NULL)+
    theme(axis.ticks = element_blank(),
      panel.background=element_blank(),
      panel.grid=element_blank())

  p3 <- ggplot(data,aes(y = y,fill=group))+
    geom_density(alpha=0.5)+
    scale_y_continuous(expand = c(0,0))+
    theme_minimal()+ labs(y=NULL)+
    theme(panel.background=element_blank(),
      panel.grid=element_blank())
 
  p1 %>%  insert_top(p2,height = 0.5)%>%
    insert_right(p3,width = 0.5)