R/geom_double_violin.R

In norment/normentR: NORMENT's Collected Plotting and Functionality Package for R

GeomDoubleViolin <- ggproto("GeomDoubleViolin", GeomViolin, 
                            draw_group = function(self, data, ..., draw_quantiles = NULL) {
                              data <- transform(data, xminv = x - violinwidth * (x - xmin), xmaxv = x + violinwidth * (xmax - x))
                              grp <- data[1, "group"]
                              newdata <- plyr::arrange(transform(data, x = if (grp %% 2 == 1) xminv else xmaxv), if (grp %% 2 == 1) y else -y)
                              newdata <- rbind(newdata[1, ], newdata, newdata[nrow(newdata), ], newdata[1, ])
                              newdata[c(1, nrow(newdata) - 1, nrow(newdata)), "x"] <- round(newdata[1, "x"])
                              
                              if (length(draw_quantiles) > 0 & !scales::zero_range(range(data$y))) {
                                stopifnot(all(draw_quantiles >= 0), all(draw_quantiles <=
                                                                          1))
                                quantiles <- ggplot2:::create_quantile_segment_frame(data, draw_quantiles)
                                aesthetics <- data[rep(1, nrow(quantiles)), setdiff(names(data), c("x", "y")), drop = FALSE]
                                aesthetics$alpha <- rep(1, nrow(quantiles))
                                both <- cbind(quantiles, aesthetics)
                                quantile_grob <- GeomPath$draw_panel(both, ...)
                                ggplot2:::ggname("geom_double_violin", grid::grobTree(GeomPolygon$draw_panel(newdata, ...), quantile_grob))
                              }
                              else {
                                ggplot2:::ggname("geom_double_violin", GeomPolygon$draw_panel(newdata, ...))
                              }
                            })

#' Double violin plot
#'
#' Violin plot split across a binary group. Particularly usefulf for checking distributions across sex,
#' or comparing control to patient group.
#' 
#' @export geom_double_violin

geom_double_violin <- function(mapping = NULL, data = NULL, stat = "ydensity", position = "identity", ..., 
                               draw_quantiles = NULL, trim = TRUE, scale = "area", na.rm = FALSE, 
                               show.legend = NA, inherit.aes = TRUE) {
  layer(data = data, mapping = mapping, stat = stat, geom = GeomDoubleViolin, 
        position = position, show.legend = show.legend, inherit.aes = inherit.aes, 
        params = list(trim = trim, scale = scale, draw_quantiles = draw_quantiles, na.rm = na.rm, ...))
}