RowRemapView.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
 *
 */


struct RowReMapTag : public UnaExpTag, public ViewTag {
    EXMAT_INLINE2 RowReMapTag() {}
    static char* name()
    {   return "Row remapped";  }
};

template<class Rep>
class RowReMapView : public RowReMapTag
{
public:
    typedef RowReMapView<Rep>   self_type;
    typedef RowReMapTag         exp_tag;
    typedef NullTag             extra_param_type;
    COMMON_VIEW_TYPEDEFS();

    enum {
        ROWS = super_type::COLS,
        COLS = super_type::ROWS,
        IsLinear = false,
        IsLinearRecursive = IsLinear && super_type::IsLinearRecursive,
        TNOP = 0,
        ENOP = 0,
        EXPLevel = Rep::EXPLevel + 1
    };

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

    /************************************************/
    // Constructors
    EXMAT_INLINE2 RowReMapView(super_type& mat)
        : rep(mat)
    {
        InitTable();
    }
    template<class Rep2> EXMAT_INLINE2
    RowReMapView(const Rep2& self, super_type& mat)
        : rep(mat)
    {
        memcpy(rowMap, self.rowMap, sizeof(rowMap));
    }

    EXMAT_INLINE2 self_type operator=(const_param_type s) {
        rep = s;
        return *this;
    }
    /************************************************/
    // Dimension information
    EXMAT_INLINE2 size_t size() const { return rep.size(); }
    EXMAT_INLINE2 size_t rows() const { return rep.cols(); }
    EXMAT_INLINE2 size_t cols() const { return rep.rows(); }
    /************************************************/
    // Index function (for internal use, no error checking applied)
    EXMAT_INLINE2 reference setAt(index_type i) {
        if(ROWS == 1)
            return rep.setAt(i);
        else
            return rep.setAt(rowMap[i/rep.cols()], i%rep.cols());
    }
    EXMAT_INLINE2 const_reference getAt(index_type i) const {
        if(ROWS == 1)
            return rep.getAt(i);
        else
            return rep.getAt(rowMap[i/rep.cols()], i%rep.cols());
    }
    EXMAT_INLINE2 reference setAt(index_type i, index_type j) {
        return rep.setAt(rowMap[i], j);
    }
    EXMAT_INLINE2 const_reference getAt(index_type i, index_type j) const
    {   return rep.getAt(rowMap[i], j); }

    // Functions for re-mapping the row index
    // Do exchange of index
    EXMAT_INLINE2 void exchange(index_type r1, index_type r2) {
        // Or use bitwise tricks to do swaping
        index_type tmp = rowMap[r2];
        rowMap[r2] = rowMap[r1];
        rowMap[r1] = tmp;
    }

private:
    EXMAT_INLINE2 void InitTable() {
        for(index_type i=0; i<ROWS; ++i)
            rowMap[i] = i;
    }
private:
    index_type rowMap[ROWS];
};

template<class Rep, class ErrChk> EXMAT_INLINE2 static
Mat<ExpMat<RowReMapView<typename Rep::rep_type> >, ErrChk>
rowremap(Mat<Rep, ErrChk>& mat) {
    return ExpMat<RowReMapView<TTYPENAME Rep::rep_type> >(mat);
}

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