Cofactors.h

/*
 * Expression Template Matrix Library
 *
 * Copyright (C) 2004 - 2006 Ricky Lung <mtlung@users.sourceforge.net>
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 */


// Forward declaration
template<class Rep> class ConstCofactorsView;

template<class Rep>
class ConstCofactorsView : public CofactorsViewTag
{
public:
    typedef ConstCofactorsView<Rep> self_type;
    typedef CofactorsViewTag            exp_tag;
    typedef NullTag                         extra_param_type;

    //COMMON_CONST_VIEW_TYPEDEFS();
    typedef typename Rep::rep_type                  super_type;
    typedef self_type                               rep_type;
    typedef super_type                              inner_rep_type;
    typedef self_type                               const_view_type;
    typedef typename super_type::row_type           row_type;
    typedef const ExpRow<self_type>                 const_row_type;
    typedef typename super_type::col_type           col_type;
    typedef typename super_type::value_type         value_type;
    typedef value_type                              reference;
    typedef const value_type                        const_reference;
    typedef typename super_type::index_type         index_type;
    typedef typename super_type::param_type         param_type;
    typedef typename super_type::const_param_type   const_param_type;
    typedef const_mat_iterator<self_type>           iterator;
    typedef const_mat_iterator<self_type>           const_iterator;
    typename OperandTypeChooser<super_type>::RET    rep;
    EXMAT_INLINE2 const_iterator begin() const
    {   return const_iterator(*this, 0, 0); }
    EXMAT_INLINE2 const_iterator end() const
    {   return const_iterator(*this, rows(), 0);    }

    enum {
        ROWS = super_type::COLS,
        COLS = super_type::ROWS,
        IsLinear = false,
        IsLinearRecursive = IsLinear && super_type::IsLinearRecursive,
        ENOP = (ROWS == 0 || COLS == 0) ? -1 :
            DynConstMinorView<Rep>::TNOP +                      // Complexity of accessing the minor
            exmat::PNS::DeterminantComplexity<ROWS-1>::RET +    // Complexity of the determinant only
            4,                                                  // Complexity of *, +, %, ==
        TNOP = (ROWS == 0 || COLS == 0) ? -1 : ENOP * ROWS * COLS,
        EXPLevel = Rep::EXPLevel + 1
    };

    typedef Mat<DenseMatCon<value_type,ROWS,COLS>, EmptyErrorChecker> temp_type;

    /************************************************/
    // Constructors
    EXMAT_INLINE2 ConstCofactorsView(const self_type& self)
        : rep(self.rep) {}
    EXMAT_INLINE2 ConstCofactorsView(const Rep& mat)
        : rep(mat) { ComErrCheck(); }
    template<class Rep2> EXMAT_INLINE2
    ConstCofactorsView(const Rep2& self, const Rep& mat)
        : rep(mat) {}

    /************************************************/
    // Dimension information
    EXMAT_INLINE2 size_t size() const { return rep.size(); }
    EXMAT_INLINE2 size_t rows() const { return rep.rows(); }
    EXMAT_INLINE2 size_t cols() const { return rep.cols(); }
    /************************************************/
    // Index function (for internal use, no error checking applied)
    EXMAT_INLINE2 const_reference getAt(index_type i) const
    {   return this->getAt(i/cols(), i%cols()); }
    EXMAT_INLINE2 const_reference getAt(index_type i, index_type j) const {
        return determinant(
            minor( Mat<ExpMat<ConstDummyView<TTYPENAME Rep::rep_type> >, EmptyErrorChecker>(
                ExpMat<ConstDummyView<TTYPENAME Rep::rep_type> >(rep)
            ), i, j)
        ) * ( (i+j) % 2 == 0 ? 1 : -1 );
    }

private:
    // Compatibility error checking
    EXMAT_INLINE2 void ComErrCheck() {
        DefaultErrorChecker::AssertCompat(
            rows() == cols()
        );
    }
};
template<class Rep, class ErrChk> EXMAT_INLINE2 static
const Mat<ExpMat<ConstCofactorsView<Rep> >, ErrChk>
cofactors(const Mat<Rep, ErrChk>& mat) {
    return Mat<ExpMat<ConstCofactorsView<Rep> >, ErrChk>(
        ExpMat<ConstCofactorsView<Rep> >(mat)
    );
}

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