swarmplot, visualise continuous distribution by a catergorical stratification variable.

swarmplot.r

# data
set.seed(1234)
bimodal <- c(rnorm(250, -2, 0.6), rnorm(250, 2, 0.6))
uniform <- runif(500, -4, 4)
normal <- rnorm(500, 0, 1.5)
dataf <- data.frame (group = rep(c("bimodal","uniform", "normal"), each = 500), xv = c(bimodal, uniform, normal), cg = rep( c("A","B"), 750))

require(beeswarm)

# hexagon 
beeswarm(xv ~ group, data = dataf, 
         method = 'hex',
         pch = 16, pwcol = as.numeric(cg),
         xlab = '', ylab = 'xv',
         labels = c('bimodal', 'uniform', 'normal'))