docs: def plotMDS(inputFileName, outPrefix, populationFileName, options):
      """Plots the MDS value.
  
      :param inputFileName: the name of the ``mds`` file.
      :param outPrefix: the prefix of the output files.
      :param populationFileName: the name of the population file.
      :param options: the options
  
      :type inputFileName: str
      :type outPrefix: str
      :type populationFileName: str
      :type options: argparse.Namespace
  
      Plots the ``mds`` value according to the ``inputFileName`` file (``mds``)
      and the ``populationFileName`` (the population file).
  
      """
      # The options
      plotMDS_options = Dummy()
      plotMDS_options.file = inputFileName
      plotMDS_options.out = outPrefix
      plotMDS_options.format = options.format
      plotMDS_options.title = options.title
      plotMDS_options.xlabel = options.xlabel
      plotMDS_options.ylabel = options.ylabel
      plotMDS_options.population_file = populationFileName
  
      try:
          # Checking the options
          PlotMDS.checkArgs(plotMDS_options)
  
          # Reading the population file
          populations = PlotMDS.readPopulations(plotMDS_options.population_file)
  
          # Getting the data
          data, labels = PlotMDS.extractData(plotMDS_options.file, populations)
          order = [labels.index("CEU"), labels.index("YRI"),
                   labels.index("JPT-CHB"), labels.index("SOURCE")]
          if "HIGHLIGHT" in labels:
              order.append(labels.index("HIGHLIGHT"))
          color = [(0.215686275, 0.000494118, 0.721568627),
                   (0.301960784, 0.68627451, 0.290196078),
                   (0.596078431, 0.305882353, 0.639215686),
                   (0.894117647, 0.101960784, 0.109803922),
                   (0.596078431, 0.305882353, 0.639215686)]
          sizes = [12, 12, 12, 8, 12]
          markers = [".", ".", ".", "+", "D"]
  
          # Plotting the data
          PlotMDS.plotMDS(data, order, labels, color, sizes, markers,
                          plotMDS_options)
  
      except PlotMDS.ProgramError as e:
          msg = "PlotMDS: %s" % e
          raise ProgramError(msg)