R/m_boxplot.R

In sebmader/LizardsAndNiches: Handleing specific data frames of lizard morphology and reflectance data

#' @title Function for simple boxplot
#'   for statistical analysis
#' @name m_boxplot
#' @param x factor vector for catigorical variable on x axis
#' @param y vector for response variable on y axis
#' @param fill potential second factor to take into account
#' @param labs vector of two elements for axis labels
#'   (c("x label", "y label))
# @importFrom ggplot2 ggplot aes geom_boxplot scale_x_discrete theme_bw geom_point labs
# position_jitterdodge position_jitter scale_fill_discrete
#' @export

# require(assertthat)
# require(ggplot2)

m_boxplot <- function(x, y, labs = c("", "", ""), fill = c("")) {

  assertthat::assert_that(is.factor(x))
  assertthat::assert_that(is.vector(y))
  assertthat::are_equal(length(x), length(y))
  assertthat::assert_that(is.vector(labs))
  assertthat::assert_that(length(labs) <= 3)

  # display sample sizes in variable names for each category
  lvls <- levels(x)
  names_with_N <- vector(mode = "character", length = length(lvls))
  for(pos in 1:length(lvls)) {
    name = lvls[pos]
    n <- length(x[which(x == name)])
    names_with_N[pos] <- paste0(name, " (", "n = ", n, ")")
  }

  if(is.factor(fill)) {

    lvls2 <- levels(fill)
    names_with_N2 <- vector(mode = "character", length = length(lvls2))
    for(pos in 1:length(lvls2)) {
      name = lvls2[pos]
      n <- length(fill[which(fill == name)])
      names_with_N2[pos] <- paste0(name, " (", "n = ", n, ")")
    }

    ggplot2::ggplot(mapping = ggplot2::aes(x = x, y = y, fill = fill))+
      ggplot2::geom_boxplot()+
      ggplot2::scale_x_discrete(labels = names_with_N)+
      ggplot2::scale_fill_discrete(labels = names_with_N2)+
      ggplot2::theme_bw()+
      ggplot2::geom_point(mapping = ggplot2::aes(fill = fill),
                 size = 1.5,
                 pch = 21,
                 position = ggplot2::position_jitterdodge(jitter.width = 0.2))+
      ggplot2::labs(x = labs[1], y = labs[2], fill = labs[3])
  } else {

    ggplot2::ggplot(mapping = ggplot2::aes(x = x, y = y))+
      ggplot2::geom_boxplot()+
      ggplot2::scale_x_discrete(labels = names_with_N)+
      ggplot2::theme_bw()+
      ggplot2::geom_point(size = 1.5,
                 position = ggplot2::position_jitter(width = 0.05),
                 pch = 21,
                 colour = "darkgrey",
                 fill = "grey")+
      ggplot2::labs(x = labs[1], y = labs[2])
  }
}