BCEA: Bayesian Cost Effectiveness Analysis

#' @param pos Parameter to set the position of the legend (only relevant for
#'            multiple interventions, ie more than 2 interventions being compared).
#'            Can be given in form
#'            of a string `(bottom|top)(right|left)` for base graphics and
#'            `bottom|top|left|right` for ggplot2. It can be a two-elements vector,
#'            which specifies the relative position on the x and y axis respectively, or
#'            alternatively it can be in form of a logical variable, with `FALSE`
#'            indicating to use the default position and `TRUE` to place it on the
#'            bottom of the plot.