code: public final float[] score( Frame fr, boolean exact, int row ) {
      double tmp[] = new double[fr.numCols()];
      for( int i=0; i<tmp.length; i++ )
        tmp[i] = fr.vecs()[i].at(row);
      return score(fr.names(),fr.domains(),exact,tmp);
    }
docs: Single row scoring, on a compatible Frame.