3d-like density plots

3-d_like_density_plots

library(dplyr)
library(tidyr)
library(ggplot2)
library(gridExtra)

df = as.data.frame(setNames(lapply(jitter(sample(-2:2, 8, T)), function(x) rnorm(100, x)), c(LETTERS[1:8]))) %>% 
  gather("var", "value", A:H)

ggplot(df, aes(x=value)) +
  geom_density(fill="black", col="white", lwd=1) +
  facet_grid(var~., switch="y") +
  theme(strip.text.x=element_blank(), panel.background=element_blank(),
        panel.spacing.y=unit(-1, "cm"), panel.grid=element_blank(),
        axis.ticks.y=element_blank(), axis.text.y=element_blank())