code: public double[] map( Map<String, Double> row, double data[] ) {
      String[] colNames = getNames();
      for( int i=0; i<colNames.length-1; i++ ) {
        Double d = row.get(colNames[i]);
        data[i] = d==null ? Double.NaN : d;
      }
      return data;
    }
docs: Takes a HashMap mapping column names to doubles.
  <p>
  Looks up the column names needed by the model, and places the doubles into the data array in
  the order needed by the model. Missing columns use NaN.
  </p>