ggplot2小提琴情节:只填充中央95%？

Question

ggplot2可以创建一个非常有吸引力的填充小提琴情节:

ggplot() + geom_violin(data=data.frame(x=1, y=rnorm(10 ^ 5)), 
    aes(x=x, y=y), fill='gray90', color='black') + 
    theme_classic()

如果可能的话,我想将填充限制在95%的分布中心,保持轮廓完整.有没有人有关于如何做到这一点的建议？

Answer 1

这样做你想要的吗？它需要一些数据处理和两把小提琴的绘制.

set.seed(1)
dat <- data.frame(x=1, y=rnorm(10 ^ 5))

#calculate for each point if it's central or not
dat_q <- quantile(dat$y, probs=c(0.025,0.975))
dat$central <- dat$y>dat_q[1] & dat$y < dat_q[2]

#plot; one'95' violin and one 'all'-violin with transparent fill.
p1 <- ggplot(data=dat, aes(x=x,y=y)) +
  geom_violin(data=dat[dat$central,], color="transparent",fill="gray90")+
  geom_violin(color="black",fill="transparent")+

  theme_classic()

编辑:圆润的边缘困扰我,所以这是第二种方法.如果我这样做,我会想要直线.所以我做了一些玩密度(这是小提琴图所基于的)

d_y <- density(dat$y)

right_side <- data.frame(x=d_y$y, y=d_y$x) #note flip of x and y, prevents coord_flip later
right_side$central <- right_side$y > dat_q[1]&right_side$y < dat_q[2]

#add the 'left side', this entails reversing the order of the data for
#path and polygon
#and making x  negative
left_side <- right_side[nrow(right_side):1,]
left_side$x <- 0 - left_side$x

density_dat <- rbind(right_side,left_side)


p2 <- ggplot(density_dat, aes(x=x,y=y)) +
  geom_polygon(data=density_dat[density_dat$central,],fill="red")+
  geom_path()


p2