// Copyright (C) 2006 Davis E. King (davis@dlib.net)
// License: Boost Software License See LICENSE.txt for the full license.
#ifndef DLIB_MATRIx_EXP_h_
#define DLIB_MATRIx_EXP_h_
#include "../algs.h"
#include "../is_kind.h"
#include "matrix_fwd.h"
#include "matrix_exp_abstract.h"
#include <iterator>
namespace dlib
{
// ----------------------------------------------------------------------------------------
// We want to return the compile time constant if our NR and NC dimensions
// aren't zero but if they are then we want to call ref_.nx() and return
// the correct values.
template < typename exp_type, long NR >
struct get_nr_helper
{
static inline long get(const exp_type&) { return NR; }
};
template < typename exp_type >
struct get_nr_helper<exp_type,0>
{
static inline long get(const exp_type& m) { return m.nr(); }
};
template < typename exp_type, long NC >
struct get_nc_helper
{
static inline long get(const exp_type&) { return NC; }
};
template < typename exp_type >
struct get_nc_helper<exp_type,0>
{
static inline long get(const exp_type& m) { return m.nc(); }
};
template <typename EXP>
struct matrix_traits
{
typedef typename EXP::type type;
typedef typename EXP::const_ret_type const_ret_type;
typedef typename EXP::mem_manager_type mem_manager_type;
typedef typename EXP::layout_type layout_type;
const static long NR = EXP::NR;
const static long NC = EXP::NC;
const static long cost = EXP::cost;
};
// ----------------------------------------------------------------------------------------
template <typename EXP> class matrix_exp;
template <typename EXP>
class matrix_exp_iterator : public std::iterator<std::forward_iterator_tag, typename matrix_traits<EXP>::type>
{
friend class matrix_exp<EXP>;
matrix_exp_iterator(const EXP& m_, long r_, long c_)
{
r = r_;
c = c_;
nc = m_.nc();
m = &m_;
}
public:
matrix_exp_iterator() : r(0), c(0), nc(0), m(0) {}
typedef typename matrix_traits<EXP>::type type;
typedef type value_type;
typedef typename matrix_traits<EXP>::const_ret_type const_ret_type;
bool operator == ( const matrix_exp_iterator& itr) const
{ return r == itr.r && c == itr.c; }
bool operator != ( const matrix_exp_iterator& itr) const
{ return !(*this == itr); }
matrix_exp_iterator& operator++()
{
++c;
if (c==nc)
{
c = 0;
++r;
}
return *this;
}
matrix_exp_iterator operator++(int)
{
matrix_exp_iterator temp(*this);
++(*this);
return temp;
}
const_ret_type operator* () const { return (*m)(r,c); }
private:
long r, c;
long nc;
const EXP* m;
};
// ----------------------------------------------------------------------------------------
template <
typename EXP
>
class matrix_exp
{
/*!
REQUIREMENTS ON EXP
EXP should be something convertible to a matrix_exp. That is,
it should inherit from matrix_exp
!*/
public:
typedef typename matrix_traits<EXP>::type type;
typedef type value_type;
typedef typename matrix_traits<EXP>::const_ret_type const_ret_type;
typedef typename matrix_traits<EXP>::mem_manager_type mem_manager_type;
typedef typename matrix_traits<EXP>::layout_type layout_type;
const static long NR = matrix_traits<EXP>::NR;
const static long NC = matrix_traits<EXP>::NC;
const static long cost = matrix_traits<EXP>::cost;
typedef matrix<type,NR,NC,mem_manager_type,layout_type> matrix_type;
typedef EXP exp_type;
typedef matrix_exp_iterator<EXP> iterator;
typedef matrix_exp_iterator<EXP> const_iterator;
inline const_ret_type operator() (
long r,
long c
) const
{
DLIB_ASSERT(r < nr() && c < nc() && r >= 0 && c >= 0,
"\tconst type matrix_exp::operator(r,c)"
<< "\n\tYou must give a valid row and column"
<< "\n\tr: " << r
<< "\n\tc: " << c
<< "\n\tnr(): " << nr()
<< "\n\tnc(): " << nc()
<< "\n\tthis: " << this
);
return ref()(r,c);
}
const_ret_type operator() (
long i
) const
{
COMPILE_TIME_ASSERT(NC == 1 || NC == 0 || NR == 1 || NR == 0);
DLIB_ASSERT(nc() == 1 || nr() == 1,
"\tconst type matrix_exp::operator(i)"
<< "\n\tYou can only use this operator on column or row vectors"
<< "\n\ti: " << i
<< "\n\tnr(): " << nr()
<< "\n\tnc(): " << nc()
<< "\n\tthis: " << this
);
DLIB_ASSERT( ((nc() == 1 && i < nr()) || (nr() == 1 && i < nc())) && i >= 0,
"\tconst type matrix_exp::operator(i)"
<< "\n\tYou must give a valid row/column number"
<< "\n\ti: " << i
<< "\n\tnr(): " << nr()
<< "\n\tnc(): " << nc()
<< "\n\tthis: " << this
);
if (nc() == 1)
return ref()(i,0);
else
return ref()(0,i);
}
long size (
) const { return nr()*nc(); }
long nr (
) const { return get_nr_helper<exp_type,NR>::get(ref()); }
long nc (
) const { return get_nc_helper<exp_type,NC>::get(ref()); }
template <typename U>
bool aliases (
const matrix_exp<U>& item
) const { return ref().aliases(item); }
template <typename U>
bool destructively_aliases (
const matrix_exp<U>& item
) const { return ref().destructively_aliases(item); }
inline const exp_type& ref (
) const { return *static_cast<const exp_type*>(this); }
inline operator const type (
) const
{
COMPILE_TIME_ASSERT(NC == 1 || NC == 0);
COMPILE_TIME_ASSERT(NR == 1 || NR == 0);
DLIB_ASSERT(nr() == 1 && nc() == 1,
"\tmatrix_exp::operator const type() const"
<< "\n\tYou can only use this operator on a 1x1 matrix"
<< "\n\tnr(): " << nr()
<< "\n\tnc(): " << nc()
<< "\n\tthis: " << this
);
// Put the expression contained in this matrix_exp into
// a temporary 1x1 matrix so that the expression will encounter
// all the overloads of matrix_assign() and have the chance to
// go through any applicable optimizations.
matrix<type,1,1,mem_manager_type,layout_type> temp(ref());
return temp(0);
}
const_iterator begin() const { return matrix_exp_iterator<EXP>(ref(),0,0); }
const_iterator end() const { return matrix_exp_iterator<EXP>(ref(),nr(),0); }
protected:
matrix_exp() {}
matrix_exp(const matrix_exp& ) {}
private:
matrix_exp& operator= (const matrix_exp&);
};
// ----------------------------------------------------------------------------------------
// something is a matrix if it is convertible to a matrix_exp object
template <typename T>
struct is_matrix<T, typename enable_if<is_convertible<T, const matrix_exp<typename T::exp_type>& > >::type >
{ static const bool value = true; };
/*
is_matrix<T>::value == 1 if T is a matrix type else 0
*/
// ----------------------------------------------------------------------------------------
template <
typename EXP
>
class matrix_diag_exp : public matrix_exp<EXP>
{
/*!
This is a matrix expression type used to represent diagonal matrices.
That is, square matrices with all off diagonal elements equal to 0.
!*/
protected:
matrix_diag_exp() {}
matrix_diag_exp(const matrix_diag_exp& item ):matrix_exp<EXP>(item) {}
};
// ----------------------------------------------------------------------------------------
}
#endif // DLIB_MATRIx_EXP_h_