docs: private double[] parseVector(String s) {
      String[] entries = WHITESPACE_PATTERN.split(s);
      double[] d = new double[entries.length];
      for(int i = 0; i < entries.length; i++) {
        try {
          d[i] = ParseUtil.parseDouble(entries[i]);
        }
        catch(NumberFormatException e) {
          throw new AbortException("Could not parse vector.");
        }
      }
      return d;
    }