public static Matrice createSubMatrix(Matrice matrix, int excluding_row, int excluding_col) 
        {
            Matrice mat;
            if(excluding_row==-1)
                mat = new Matrice(matrix.getNbLines(), matrix.getNbColumns()-1);
            else if(excluding_col==-1)
                mat = new Matrice(matrix.getNbLines()-1, matrix.getNbColumns());
            else{
                mat = new Matrice(matrix.getNbLines()-1, matrix.getNbColumns()-1);
            }

            int r = -1;
            
            for (int i=0;i<matrix.getNbLines();i++) 
            {
                if (i==excluding_row)
                    continue;
                    r++;
                    int c = -1;
                for (int j=0;j<matrix.getNbColumns();j++) {
                    if (j==excluding_col)
                        continue;
                    mat.setValueAt(r, ++c, matrix.getValueAt(i, j));
                }
            }
            return mat;
        }