R/psm_plot.R

In alletsee/pricesensitivitymeter: Van Westendorp Price Sensitivity Meter Analysis

#---------------------
# Plotting function for standard PSM plot
#---------------------

psm_plot <- function(psm_result,
                     shade_pricerange = TRUE,
                     line_toocheap = TRUE,
                     line_tooexpensive = TRUE,
                     line_notcheap = TRUE,
                     line_notexpensive = TRUE,
                     point_idp = TRUE,
                     point_color_idp = "#009E73",
                     label_idp = TRUE,
                     point_opp = TRUE,
                     point_color_opp = "#009E73",
                     label_opp = TRUE,
                     pricerange_color = "grey50",
                     pricerange_alpha = 0.3,
                     line_color = c(
                       "too cheap" = "#009E73",
                       "not cheap" = "#009E73",
                       "not expensive" = "#D55E00",
                       "too expensive" = "#D55E00"
                     ),
                     line_type = c(
                       "too cheap" = "dotted",
                       "not cheap" = "solid",
                       "not expensive" = "solid",
                       "too expensive" = "dotted"
                     )) {
  # ensure that only objects that are result of psm_analysis/psm_analysis_weighted are accepted as input
  stopifnot(class(psm_result) == "psm")

  # base of plot
  plot_object <- ggplot2::ggplot(data = psm_result$data_vanwestendorp, ggplot2::aes(x = .data$price))

  # shaded area for acceptable pricerange
  if (isTRUE(shade_pricerange)) {
    plot_object <- plot_object + ggplot2::annotate(
      geom = "rect",
      xmin = psm_result$pricerange_lower,
      xmax = psm_result$pricerange_upper,
      ymin = 0, ymax = Inf,
      fill = pricerange_color, alpha = pricerange_alpha
    )
  }

  # line for "too cheap"
  if (isTRUE(line_toocheap)) {
    plot_object <- plot_object + ggplot2::geom_line(ggplot2::aes(
      y = .data$ecdf_toocheap,
      colour = "too cheap",
      linetype = "too cheap"
    ),
    size = 1
    )
  }

  # line for "too expensive"
  if (isTRUE(line_tooexpensive)) {
    plot_object <- plot_object + ggplot2::geom_line(ggplot2::aes(
      y = .data$ecdf_tooexpensive,
      colour = "too expensive",
      linetype = "too expensive"
    ),
    size = 1
    )
  }

  # line for "not cheap"
  if (isTRUE(line_notcheap)) {
    plot_object <- plot_object + ggplot2::geom_line(ggplot2::aes(
      y = .data$ecdf_not_cheap,
      colour = "not cheap",
      linetype = "not cheap"
    ),
    size = 1
    )
  }

  # line for "not expensive"
  if (isTRUE(line_notexpensive)) {
    plot_object <- plot_object + ggplot2::geom_line(ggplot2::aes(
      y = .data$ecdf_not_expensive,
      colour = "not expensive",
      linetype = "not expensive"
    ),
    size = 1
    )
  }


  # point for Indifference Price Point (intersection of "cheap" and "expensive")
  if (isTRUE(point_idp)) {
    plot_object <- plot_object + ggplot2::annotate(
      geom = "point",
      x = psm_result$idp,
      y = psm_result$data_vanwestendorp$ecdf_not_cheap[psm_result$data_vanwestendorp$price == psm_result$idp],
      size = 5,
      shape = 18,
      colour = point_color_idp
    )
  }

  # point for Optimal Price Point (intersection of "too cheap" and "too expensive")
  if (isTRUE(point_idp)) {
    plot_object <- plot_object + ggplot2::annotate(
      geom = "point",
      x = psm_result$opp,
      y = psm_result$data_vanwestendorp$ecdf_toocheap[psm_result$data_vanwestendorp$price == psm_result$opp],
      size = 3,
      shape = 17,
      colour = point_color_opp
    )
  }


  # Adding line color and line style

  plot_object <- plot_object + ggplot2::scale_colour_manual(name = "Legend", values = line_color)
  plot_object <- plot_object + ggplot2::scale_linetype_manual(name = "Legend", values = line_type)

  # Adding label for Indifference Price Point

  if (isTRUE(label_idp)) {
    plot_object <- plot_object + ggplot2::annotate(
      geom = "label",
      x = psm_result$idp,
      y = psm_result$data_vanwestendorp$ecdf_not_cheap[psm_result$data_vanwestendorp$price == psm_result$idp],
      label = paste("IDP: ", format(psm_result$idp, nsmall = 2)),
      fill = "white",
      alpha = 0.5
    )
  }


  if (isTRUE(label_opp)) {
    plot_object <- plot_object + ggplot2::annotate(
      geom = "label",
      x = psm_result$opp,
      y = psm_result$data_vanwestendorp$ecdf_toocheap[psm_result$data_vanwestendorp$price == psm_result$opp],
      label = paste("OPP: ", format(psm_result$opp, nsmall = 2)),
      fill = "white",
      alpha = 0.5
    )
  }

  # return the resulting ggplot object
  return(plot_object)
}