R/type_ribbon.R

In tinyplot: Lightweight Extension of the Base R Graphics System

type_ribbon = function(datapoints, xlabs) {
  # Convert x to factor if it's not already
  if (is.character(datapoints$x)) {
    datapoints$x = as.factor(datapoints$x)
  }

  if (is.factor(datapoints$x)) {
    xlvls = levels(datapoints$x)
    xlabs = seq_along(xlvls)
    names(xlabs) = xlvls
    datapoints$x = as.integer(datapoints$x)
  } else {
    xlabs = NULL
  }

  # Handle ordering based on by and facet variables
  null_by = length(unique(datapoints$by)) == 1
  null_facet = length(unique(datapoints$facet)) == 1

  if (null_by && null_facet) {
    xord = order(datapoints$x)
  } else if (null_facet) {
    xord = order(datapoints$by, datapoints$x)
  } else if (null_by) {
    xord = order(datapoints$facet, datapoints$x)
  } else {
    xord = order(datapoints$by, datapoints$facet, datapoints$x)
  }
  
  # Reorder x, y, ymin, and ymax based on the order determined
  datapoints = datapoints[xord,]
  
  out = list(
    x = datapoints$x,
    y = datapoints$y,
    ymin = datapoints$ymin,
    ymax = datapoints$ymax,
    xlabs = xlabs,
    datapoints = datapoints)

  if (length(unique(datapoints$by)) > 1) out[["by"]] = datapoints$by
  if (length(unique(datapoints$facet)) > 1) out[["facet"]] = datapoints$facet

  return(out)
}