docs: def printConcordance(concordance, prefix):
      """Print the concordance.
  
      :param concordance: the concordance of each sample.
      :param prefix: the prefix of all the files.
  
      :type concordance: dict
      :type prefix: str
  
      :returns: the concordance percentage (dict)
  
      The concordance is the number of genotypes that are equal when comparing a
      duplicated samples with another one, divided by the total number of
      genotypes (excluding genotypes that are no call [*i.e.* ``0``]). If a
      duplicated sample has 100% of no calls, the concordance will be zero.
  
      The file ``prefix.concordance`` will contain :math:`N \\times N` matrices
      for each set of duplicated samples.
  
      """
      outFile = None
      try:
          outFile = open(prefix + ".concordance", "w")
      except IOError:
          msg = "%s: can't write file" % prefix + ".concordance"
          raise ProgramError(msg)
  
      concordance_percentage = {}
      for key in concordance.iterkeys():
          print >>outFile, "#%s\t%s" % key
  
          # Doing the division
          none_zero = concordance[key][1] != 0
          true_concordance = np.zeros(np.multiply(*concordance[key][1].shape))
          true_concordance[np.ravel(none_zero)] = np.true_divide(
              concordance[key][0][none_zero],
              concordance[key][1][none_zero],
          )
          true_concordance.shape = concordance[key][1].shape
          true_concordance = np.asmatrix(true_concordance)
          concordance_percentage[key] = true_concordance
  
          output = StringIO.StringIO()
          np.savetxt(output, true_concordance, delimiter="\t", fmt="%.8f")
          print >>outFile, output.getvalue().rstrip("\r\n")
  
      outFile.close()
  
      return concordance_percentage