public static double[][] F(Instances D){
  int L=D.classIndex();
  double M[][]=new double[L][L];
  for (int j=0; j < L; j++) {
    for (int k=j + 1; k < L; k++) {
      M[j][k]=Math.abs(1. - f(D,j,k));
    }
  }
  return M;
}

public static double [ ] [ ] F ( Instances D ) { int L = D . classIndex ( ) ; double M [ ] [ ] = new double [ L ] [ L ] ; for ( int j = 0 ; j < L ; j ++ ) { for ( int k = j + 1 ; k < L ; k ++ ) { M [ j ] [ k ] = Math . abs ( 1. - f ( D , j , k ) ) ; } } return M ; }
f - relative frequency matrix ( between p ( j ) , p ( k ) and p ( j , k ) ) in dataset d .
