R/archive/pie_chart_eumelareg.R

In MBender1992/emR: Dictionary for EuMelaReg functions (analysis of clinical studies)

#' Pie Chart in EuMelaReg style
#'
#' This code generates a pie chart to show distribution of variables.
#' @param y Vector with group names (as character or factor).
#' @param text.color Color of the text within the chart to display percentages.
#' @param text.size Size of the text within the chart.
#' @param x.pos Position of text labels. Decrease to get closer to the origin and increase to move text towards the outer border.
#' @param cols Color scheme for the pie chart. Can be an \code{emr_cols} object or manual scale.
#' @param title Plot title.
#' @param jco.alpha Transparency level, a real number between 0 and 1. Only used if cols = NULL.
#' @export

pie_chart_eumelareg <- function(y, text.color = "white",text.size = 6,x.pos = 1.2, cols = NULL,jco.alpha = 1, title=NULL){
  df <- group <- value <- NULL
  df <- as.data.frame(table(y)/length(y))
  colnames(df) <- c("group", "value")

  ggplot(df, aes(x="", y=value, fill=group)) +
    geom_bar(stat="identity", width=1, color = "white")+
    coord_polar("y", start=0) +
    geom_text(aes(label = paste0(round(value*100), "%"), x = x.pos),
              position = position_stack(vjust = 0.5), color = text.color, size = text.size) +
    labs(x = NULL, y = NULL, fill = NULL, title = title) +
    theme_eumelareg_pie_chart() +
    if (!is.null(cols)){
      scale_fill_manual(values = cols)
    } else {
      ggsci::scale_fill_jco(alpha = jco.alpha)
    }
}