Create raincloud plots with ggplot2

raincloud.R

raincloudplot <- function(data, y, fill, x = fill, cols = NULL,
                          boxplots = c("below", "in", "none")) {
  
  require(dplyr)
  require(ggplot2)
  source("https://raw.githubusercontent.com/datavizpyr/data/master/half_flat_violinplot.R")
  
  boxplots <- match.arg(boxplots)

  p <- ggplot(data, aes_string(y = y, x = x, fill = fill)) +
    geom_flat_violin(position = position_nudge(x = .2, y = 0), trim = FALSE)

  p <- p + geom_point(position = position_jitter(width = .15), size = 1,
                      pch = 21, colour = "black") +
    coord_flip() +
    theme_classic() +
    theme(legend.position = "n", panel.grid.major = element_line(),
          panel.grid.minor = element_line())

  if (boxplots == "below") {
    p <- p + geom_boxplot(width = .1, outlier.shape = NA, alpha = 0.5)
  } else if (boxplots == "in") {
    p <- p + geom_boxplot(width = .1, outlier.shape = NA, alpha = 0.5,
                          position = position_nudge(x = 0.2))
  }
  
  if (is.null(cols)) {
    n <- length(unique(data[, fill]))
    p <- p + ggplot2:::manual_scale(c("fill", "colour"), rainbow(n))
  } else {
    p <- p + ggplot2:::manual_scale(c("fill", "colour"), values = cols)
  }

  p
}