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Ublas :

From: James N. Knight (nate_at_[hidden])
Date: 2006-11-10 13:30:42


I've seen this discussed on the message board a few times before. So I thought I would post
the code I've been using. I hope this is okay.

The attached file diagonal_from_vector.hpp includes some helpful code for
dealing with diagonal matrices. The diagonal_vector_adaptor<V> creates
a matrix adaptor that is a square diagonal matrix view with the vector
on the diagonal.

The free function diagm takes a vector and returns a diagonal_vector_adaptor.

The free function diag takes a matrix and returns a matrix_vector_slice corresponding
to the diagonal.

I've also included a the file ublas_banded1.hpp which should go in bindings/traits
and allows a diagonal_matrix to be used in place of a vector. In other words, you could
do something like lapack::gesdd(A,S,U,Vt); where S is a diagonal_matrix and not a vector
which is what is expected by the call. This however, might not really be needed as
the call could be done like lapack::gesdd(A,diag(S),U,Vt) without the new traits file.

Any thoughts?

Nate
 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Sample Usage:

#include <boost/numeric/ublas/vector.hpp>
#include <boost/numeric/ublas/matrix.hpp>
#include <boost/numeric/ublas/banded.hpp>
#include <boost/numeric/ublas/io.hpp>

#include <iostream>

#include "diagonal_from_vector.hpp"

namespace ublas = boost::numeric::ublas;

int main(){

        typedef ublas::vector<double> vector;
        typedef ublas::matrix<double, ublas::column_major> matrix;

        vector s(5);
        s(0) = 1.2; s(1) = 2.2; s(2) = 3.3; s(3) = 5; s(4) = -1;

        std::cout << "s = " << s << std::endl;
        std::cout << "diag(s) = " << ublas::diagm(s) << std::endl;
        std::cout << "diag(diagm(s)) = " << ublas::diag(ublas::diagm(s)) << std::endl;
        std::cout << "diagm(2*s) = " << ublas::diagm(2*s) << std::endl;

        ublas::diagonal_matrix<double> m(5,5);
        ublas::diag(m) = s;
        std::cout << "diag(m) = s; m = " << m << std::endl;

}


/*
 *
 * Copyright (c) 2002, 2003 Kresimir Fresl, Toon Knapen and Karl Meerbergen
 *
 * Permission to copy, modify, use and distribute this software
 * for any non-commercial or commercial purpose is granted provided
 * that this license appear on all copies of the software source code.
 *
 * Authors assume no responsibility whatsoever for its use and makes
 * no guarantees about its quality, correctness or reliability.
 *
 * KF acknowledges the support of the Faculty of Civil Engineering,
 * University of Zagreb, Croatia.
 *
 */

#ifndef BOOST_NUMERIC_BINDINGS_TRAITS_UBLAS_BANDED1_H
#define BOOST_NUMERIC_BINDINGS_TRAITS_UBLAS_BANDED1_H

#include <boost/numeric/bindings/traits/traits.hpp>

#ifndef BOOST_NUMERIC_BINDINGS_POOR_MANS_TRAITS

#ifndef BOOST_UBLAS_HAVE_BINDINGS
# include <boost/numeric/ublas/banded.hpp>
#endif
#include <boost/numeric/bindings/traits/detail/ublas_ordering.hpp>

#if defined (BOOST_NUMERIC_BINDINGS_FORTRAN) || !defined (BOOST_NUMERIC_BINDINGS_NO_STRUCTURE_CHECK)
# include <boost/static_assert.hpp>
# include <boost/type_traits/same_traits.hpp>
#endif

namespace boost { namespace numeric { namespace bindings { namespace traits {

  // ublas::matrix_banded<>
  // When orientation_category==row_major_tag then the ublas banded format corresponds to
  // the LAPACK band format.
  // Specialization using matrix_detail_traits so that we can specialize for
  // matrix_detail_traits< banded<T, F, ArrT>, banded<T, F, ArrT> >
  // matrix_detail_traits< banded<T, F, ArrT>, banded<T, F, ArrT> const >
  // at once.
  template <typename T, typename F, typename ArrT, typename M>
  struct vector_detail_traits< boost::numeric::ublas::diagonal_matrix<T, F, ArrT>, M >
  {
#ifndef BOOST_NUMERIC_BINDINGS_NO_SANITY_CHECK
    BOOST_STATIC_ASSERT( (boost::is_same<boost::numeric::ublas::diagonal_matrix<T, F, ArrT>, typename boost::remove_const<M>::type>::value) );
#endif
#ifdef BOOST_NUMERIC_BINDINGS_FORTRAN
    BOOST_STATIC_ASSERT((boost::is_same<
      typename F::orientation_category,
      boost::numeric::ublas::row_major_tag
>::value));
#endif

    typedef boost::numeric::ublas::diagonal_matrix<T, F, ArrT> identifier_type ;
    typedef M vector_type;

    typedef T value_type;
    typedef typename detail::generate_const<M,T>::type* pointer;

    static pointer storage (vector_type& m) {
      typedef typename detail::generate_const<M,ArrT>::type array_type ;
      return vector_traits<array_type>::storage (m.data());
    }

    static int size (vector_type& m) { return m.size1(); }

    static int lower_bandwidth (vector_type& m) { return m.lower() ; }
    static int upper_bandwidth (vector_type& m) { return m.upper() ; }
    static int storage_size (vector_type& m) { return size1 (m) * size2 (m); }
    static int leading_dimension (vector_type& m) {
      // g++ 2.95.4 and 3.0.4 (with -pedantic) dislike
      // identifier_type::functor_type::size2()
      return lower_bandwidth(m) + upper_bandwidth(m) + 1 ;
    }

    // stride1 == distance (m (i, j), m (i+1, j))
    static int stride (vector_type& m) {
      typedef typename identifier_type::orientation_category orientation_category;
      typedef typename detail::ublas_ordering<orientation_category>::functor_type functor_t ;
      return functor_t::one2 ( std::max(m.size1(), m.size2()), leading_dimension(m)-1 ) ;
    }
    // stride2 == distance (m (i, j), m (i, j+1))
    static int stride2 (vector_type& m) {
      typedef typename identifier_type::orientation_category orientation_category;
      typedef typename detail::ublas_ordering<orientation_category>::functor_type functor_t ;
      return functor_t::one1 ( std::max(m.size1(), m.size2()), leading_dimension(m)-1 ) ;
    }
  };

}}}}

#endif // BOOST_NUMERIC_BINDINGS_POOR_MANS_TRAITS

#endif // BOOST_NUMERIC_BINDINGS_TRAITS_UBLAS_BANDED_H


#ifndef _BOOST_UBLAS_DIAGONAL_FROM_VECTOR_
#define _BOOST_UBLAS_DIAGONAL_FROM_VECTOR_

// create by James Knight 10/18/2006
// diagonal_vector_adaptor is a modified version of banded_adaptor in banded.hpp

#include <boost/numeric/ublas/matrix.hpp>
#include <boost/numeric/ublas/matrix_proxy.hpp>
#include <boost/numeric/ublas/detail/temporary.hpp>

// Iterators based on ideas of Jeremy Siek

namespace boost { namespace numeric { namespace ublas {

    template<class M>
    class diagonal_vector_adaptor :
        public matrix_expression<diagonal_vector_adaptor<M> > {

        typedef diagonal_vector_adaptor<M> self_type;
    public:
#ifdef BOOST_UBLAS_ENABLE_PROXY_SHORTCUTS
        using matrix_expression<self_type>::operator ();
#endif
        typedef const M const_matrix_type;
        typedef M matrix_type;
        typedef typename M::size_type size_type;
        typedef typename M::difference_type difference_type;
        typedef typename M::value_type value_type;
        typedef typename M::const_reference const_reference;
        typedef typename boost::mpl::if_<boost::is_const<M>,
                                          typename M::const_reference,
                                          typename M::reference>::type reference;
        typedef typename boost::mpl::if_<boost::is_const<M>,
                                          typename M::const_closure_type,
                                          typename M::closure_type>::type matrix_closure_type;
        typedef const self_type const_closure_type;
        typedef self_type closure_type;
        // Replaced by _temporary_traits to avoid type requirements on M
        //typedef typename M::vector_temporary_type vector_temporary_type;
        //typedef typename M::matrix_temporary_type matrix_temporary_type;
        typedef typename storage_restrict_traits<typename M::storage_category,
                                                 packed_proxy_tag>::storage_category storage_category;

        // Construction and destruction
        BOOST_UBLAS_INLINE
        diagonal_vector_adaptor(matrix_type &data):
            matrix_expression<self_type> (),
            data_ (data), lower_ (0), upper_ (0) {}
        BOOST_UBLAS_INLINE
        diagonal_vector_adaptor (const diagonal_vector_adaptor &m):
            matrix_expression<self_type> (),
            data_ (m.data_), lower_ (m.lower_), upper_ (m.upper_) {}

        // Accessors
        BOOST_UBLAS_INLINE
        size_type size1 () const {
            return data_.size ();
        }
        BOOST_UBLAS_INLINE
        size_type size2 () const {
            return data_.size ();
        }
        BOOST_UBLAS_INLINE
        size_type lower () const {
            return size_type();
        }
        BOOST_UBLAS_INLINE
        size_type upper () const {
            return size_type();
        }

        // Storage accessors
        BOOST_UBLAS_INLINE
        const matrix_closure_type &data () const {
            return data_;
        }
        BOOST_UBLAS_INLINE
        matrix_closure_type &data () {
            return data_;
        }

        // Element access
#ifndef BOOST_UBLAS_PROXY_CONST_MEMBER
        BOOST_UBLAS_INLINE
        const_reference operator () (size_type i, size_type j) const {
            BOOST_UBLAS_CHECK (i < size1 (), bad_index ());
            BOOST_UBLAS_CHECK (j < size2 (), bad_index ());
#ifdef BOOST_UBLAS_OWN_BANDED
            if (i == j)
                return data () (i);
#else
            if (i == j)
                return data () (i);
#endif
            return zero_;
        }
        BOOST_UBLAS_INLINE
        reference operator () (size_type i, size_type j) {
            BOOST_UBLAS_CHECK (i < size1 (), bad_index ());
            BOOST_UBLAS_CHECK (j < size2 (), bad_index ());
#ifdef BOOST_UBLAS_OWN_BANDED
            if (i == j)
                return data () (i);
#else
            if (i == j)
                return data () (i);
#endif
#ifndef BOOST_UBLAS_REFERENCE_CONST_MEMBER
            bad_index ().raise ();
#endif
            return const_cast<reference>(zero_);
        }
#else
        BOOST_UBLAS_INLINE
        reference operator () (size_type i, size_type j) const {
            BOOST_UBLAS_CHECK (i < size1 (), bad_index ());
            BOOST_UBLAS_CHECK (j < size2 (), bad_index ());
#ifdef BOOST_UBLAS_OWN_BANDED
            if (i == j)
                return data () (i);
#else
            if (i == j)
                return data () (i);
#endif
#ifndef BOOST_UBLAS_REFERENCE_CONST_MEMBER
            bad_index ().raise ();
#endif
            return const_cast<reference>(zero_);
        }
#endif

        // Assignment
        BOOST_UBLAS_INLINE
        diagonal_vector_adaptor &operator = (const diagonal_vector_adaptor &m) {
            matrix_assign<scalar_assign> (*this, m);
            return *this;
        }
        BOOST_UBLAS_INLINE
        diagonal_vector_adaptor &assign_temporary (diagonal_vector_adaptor &m) {
            *this = m;
            return *this;
        }
        template<class AE>
        BOOST_UBLAS_INLINE
        diagonal_vector_adaptor &operator = (const matrix_expression<AE> &ae) {
            matrix_assign<scalar_assign> (*this, matrix<value_type> (ae));
            return *this;
        }
        template<class AE>
        BOOST_UBLAS_INLINE
        diagonal_vector_adaptor &assign (const matrix_expression<AE> &ae) {
            matrix_assign<scalar_assign> (*this, ae);
            return *this;
        }
        template<class AE>
        BOOST_UBLAS_INLINE
        diagonal_vector_adaptor& operator += (const matrix_expression<AE> &ae) {
            matrix_assign<scalar_assign> (*this, matrix<value_type> (*this + ae));
            return *this;
        }
        template<class AE>
        BOOST_UBLAS_INLINE
        diagonal_vector_adaptor &plus_assign (const matrix_expression<AE> &ae) {
            matrix_assign<scalar_plus_assign> (*this, ae);
            return *this;
        }
        template<class AE>
        BOOST_UBLAS_INLINE
        diagonal_vector_adaptor& operator -= (const matrix_expression<AE> &ae) {
            matrix_assign<scalar_assign> (*this, matrix<value_type> (*this - ae));
            return *this;
        }
        template<class AE>
        BOOST_UBLAS_INLINE
        diagonal_vector_adaptor &minus_assign (const matrix_expression<AE> &ae) {
            matrix_assign<scalar_minus_assign> (*this, ae);
            return *this;
        }
        template<class AT>
        BOOST_UBLAS_INLINE
        diagonal_vector_adaptor& operator *= (const AT &at) {
            matrix_assign_scalar<scalar_multiplies_assign> (*this, at);
            return *this;
        }
        template<class AT>
        BOOST_UBLAS_INLINE
        diagonal_vector_adaptor& operator /= (const AT &at) {
            matrix_assign_scalar<scalar_divides_assign> (*this, at);
            return *this;
        }

        // Closure comparison
        BOOST_UBLAS_INLINE
        bool same_closure (const diagonal_vector_adaptor &ba) const {
            return (*this).data ().same_closure (ba.data ());
        }

        // Swapping
        BOOST_UBLAS_INLINE
        void swap (diagonal_vector_adaptor &m) {
            if (this != &m) {
                BOOST_UBLAS_CHECK (lower_ == m.lower_, bad_size ());
                BOOST_UBLAS_CHECK (upper_ == m.upper_, bad_size ());
                matrix_swap<scalar_swap> (*this, m);
            }
        }
        BOOST_UBLAS_INLINE
        friend void swap (diagonal_vector_adaptor &m1, diagonal_vector_adaptor &m2) {
            m1.swap (m2);
        }

        // Iterator types
    private:
        // Use the matrix iterator
        typedef typename M::const_iterator const_subiterator1_type;
        typedef typename boost::mpl::if_<boost::is_const<M>,
                                          typename M::const_iterator,
                                          typename M::iterator>::type subiterator1_type;
        typedef typename M::const_iterator const_subiterator2_type;
        typedef typename boost::mpl::if_<boost::is_const<M>,
                                          typename M::const_iterator,
                                          typename M::iterator>::type subiterator2_type;

    public:
#ifdef BOOST_UBLAS_USE_INDEXED_ITERATOR
        typedef indexed_iterator1<self_type, packed_random_access_iterator_tag> iterator1;
        typedef indexed_iterator2<self_type, packed_random_access_iterator_tag> iterator2;
        typedef indexed_const_iterator1<self_type, packed_random_access_iterator_tag> const_iterator1;
        typedef indexed_const_iterator2<self_type, packed_random_access_iterator_tag> const_iterator2;
#else
        class const_iterator1;
        class iterator1;
        class const_iterator2;
        class iterator2;
#endif
        typedef reverse_iterator_base1<const_iterator1> const_reverse_iterator1;
        typedef reverse_iterator_base1<iterator1> reverse_iterator1;
        typedef reverse_iterator_base2<const_iterator2> const_reverse_iterator2;
        typedef reverse_iterator_base2<iterator2> reverse_iterator2;

        // Element lookup
        BOOST_UBLAS_INLINE
        const_iterator1 find1 (int rank, size_type i, size_type j) const {
            if (rank == 1) {
                size_type lower_i = (std::max) (difference_type (j - upper_), difference_type (0));
                i = (std::max) (i, lower_i);
                size_type upper_i = (std::min) (j + 1 + lower_, size1 ());
                i = (std::min) (i, upper_i);
            }
            return const_iterator1 (*this, data ().find (i));
        }
        BOOST_UBLAS_INLINE
        iterator1 find1 (int rank, size_type i, size_type j) {
            if (rank == 1) {
                size_type lower_i = (std::max) (difference_type (j - upper_), difference_type (0));
                i = (std::max) (i, lower_i);
                size_type upper_i = (std::min) (j + 1 + lower_, size1 ());
                i = (std::min) (i, upper_i);
            }
            return iterator1 (*this, data ().find (i));
        }
        BOOST_UBLAS_INLINE
        const_iterator2 find2 (int rank, size_type i, size_type j) const {
            if (rank == 1) {
                size_type lower_j = (std::max) (difference_type (i - lower_), difference_type (0));
                j = (std::max) (j, lower_j);
                size_type upper_j = (std::min) (i + 1 + upper_, size2 ());
                j = (std::min) (j, upper_j);
            }
            return const_iterator2 (*this, data ().find (j));
        }
        BOOST_UBLAS_INLINE
        iterator2 find2 (int rank, size_type i, size_type j) {
            if (rank == 1) {
                size_type lower_j = (std::max) (difference_type (i - lower_), difference_type (0));
                j = (std::max) (j, lower_j);
                size_type upper_j = (std::min) (i + 1 + upper_, size2 ());
                j = (std::min) (j, upper_j);
            }
            return iterator2 (*this, data ().find (j));
        }

        // Iterators simply are indices.

#ifndef BOOST_UBLAS_USE_INDEXED_ITERATOR
        class const_iterator1:
            public container_const_reference<diagonal_vector_adaptor>,
            public random_access_iterator_base<typename iterator_restrict_traits<
                                                   typename const_subiterator1_type::iterator_category, packed_random_access_iterator_tag>::iterator_category,
                                               const_iterator1, value_type> {
        public:
            typedef typename const_subiterator1_type::value_type value_type;
            typedef typename const_subiterator1_type::difference_type difference_type;
            typedef typename const_subiterator1_type::reference reference;
            typedef typename const_subiterator1_type::pointer pointer;

            typedef const_iterator2 dual_iterator_type;
            typedef const_reverse_iterator2 dual_reverse_iterator_type;

            // Construction and destruction
            BOOST_UBLAS_INLINE
            const_iterator1 ():
                container_const_reference<self_type> (), it1_ () {}
            BOOST_UBLAS_INLINE
            const_iterator1 (const self_type &m, const const_subiterator1_type &it1):
                container_const_reference<self_type> (m), it1_ (it1) {}
            BOOST_UBLAS_INLINE
            const_iterator1 (const iterator1 &it):
                container_const_reference<self_type> (it ()), it1_ (it.it1_) {}

            // Arithmetic
            BOOST_UBLAS_INLINE
            const_iterator1 &operator ++ () {
                ++ it1_;
                return *this;
            }
            BOOST_UBLAS_INLINE
            const_iterator1 &operator -- () {
                -- it1_;
                return *this;
            }
            BOOST_UBLAS_INLINE
            const_iterator1 &operator += (difference_type n) {
                it1_ += n;
                return *this;
            }
            BOOST_UBLAS_INLINE
            const_iterator1 &operator -= (difference_type n) {
                it1_ -= n;
                return *this;
            }
            BOOST_UBLAS_INLINE
            difference_type operator - (const const_iterator1 &it) const {
                BOOST_UBLAS_CHECK (&(*this) () == &it (), external_logic ());
                return it1_ - it.it1_;
            }

            // Dereference
            BOOST_UBLAS_INLINE
            const_reference operator * () const {
                size_type i = index1 ();
                size_type j = index2 ();
                BOOST_UBLAS_CHECK (i < (*this) ().size1 (), bad_index ());
                BOOST_UBLAS_CHECK (j < (*this) ().size2 (), bad_index ());
#ifdef BOOST_UBLAS_OWN_BANDED
                size_type k = (std::max) (i, j);
                size_type l = (*this) ().lower () + j - i;
                if (k < (std::max) ((*this) ().size1 (), (*this) ().size2 ()) &&
                    l < (*this) ().lower () + 1 + (*this) ().upper ())
                    return *it1_;
#else
                size_type k = j;
                size_type l = (*this) ().upper () + i - j;
                if (k < (*this) ().size2 () &&
                    l < (*this) ().lower () + 1 + (*this) ().upper ())
                    return *it1_;
#endif
                return (*this) () (i, j);
            }

#ifndef BOOST_UBLAS_NO_NESTED_CLASS_RELATION
            BOOST_UBLAS_INLINE
#ifdef BOOST_UBLAS_MSVC_NESTED_CLASS_RELATION
            typename self_type::
#endif
            const_iterator2 begin () const {
                return (*this) ().find2 (1, index1 (), 0);
            }
            BOOST_UBLAS_INLINE
#ifdef BOOST_UBLAS_MSVC_NESTED_CLASS_RELATION
            typename self_type::
#endif
            const_iterator2 end () const {
                return (*this) ().find2 (1, index1 (), (*this) ().size2 ());
            }
            BOOST_UBLAS_INLINE
#ifdef BOOST_UBLAS_MSVC_NESTED_CLASS_RELATION
            typename self_type::
#endif
            const_reverse_iterator2 rbegin () const {
                return const_reverse_iterator2 (end ());
            }
            BOOST_UBLAS_INLINE
#ifdef BOOST_UBLAS_MSVC_NESTED_CLASS_RELATION
            typename self_type::
#endif
            const_reverse_iterator2 rend () const {
                return const_reverse_iterator2 (begin ());
            }
#endif

            // Indices
            BOOST_UBLAS_INLINE
            size_type index1 () const {
                return it1_.index ();
            }
            BOOST_UBLAS_INLINE
            size_type index2 () const {
                return it1_.index ();
            }

            // Assignment
            BOOST_UBLAS_INLINE
            const_iterator1 &operator = (const const_iterator1 &it) {
                container_const_reference<self_type>::assign (&it ());
                it1_ = it.it1_;
                return *this;
            }

            // Comparison
            BOOST_UBLAS_INLINE
            bool operator == (const const_iterator1 &it) const {
                BOOST_UBLAS_CHECK (&(*this) () == &it (), external_logic ());
                return it1_ == it.it1_;
            }
            BOOST_UBLAS_INLINE
            bool operator < (const const_iterator1 &it) const {
                BOOST_UBLAS_CHECK (&(*this) () == &it (), external_logic ());
                return it1_ < it.it1_;
            }

        private:
            const_subiterator1_type it1_;
        };
#endif

        BOOST_UBLAS_INLINE
        const_iterator1 begin1 () const {
            return find1 (0, 0, 0);
        }
        BOOST_UBLAS_INLINE
        const_iterator1 end1 () const {
            return find1 (0, size1 (), 0);
        }

#ifndef BOOST_UBLAS_USE_INDEXED_ITERATOR
        class iterator1:
            public container_reference<diagonal_vector_adaptor>,
            public random_access_iterator_base<typename iterator_restrict_traits<
                                                   typename subiterator1_type::iterator_category, packed_random_access_iterator_tag>::iterator_category,
                                               iterator1, value_type> {
        public:
            typedef typename subiterator1_type::value_type value_type;
            typedef typename subiterator1_type::difference_type difference_type;
            typedef typename subiterator1_type::reference reference;
            typedef typename subiterator1_type::pointer pointer;

            typedef iterator2 dual_iterator_type;
            typedef reverse_iterator2 dual_reverse_iterator_type;

            // Construction and destruction
            BOOST_UBLAS_INLINE
            iterator1 ():
                container_reference<self_type> (), it1_ () {}
            BOOST_UBLAS_INLINE
            iterator1 (self_type &m, const subiterator1_type &it1):
                container_reference<self_type> (m), it1_ (it1) {}

            // Arithmetic
            BOOST_UBLAS_INLINE
            iterator1 &operator ++ () {
                ++ it1_;
                return *this;
            }
            BOOST_UBLAS_INLINE
            iterator1 &operator -- () {
                -- it1_;
                return *this;
            }
            BOOST_UBLAS_INLINE
            iterator1 &operator += (difference_type n) {
                it1_ += n;
                return *this;
            }
            BOOST_UBLAS_INLINE
            iterator1 &operator -= (difference_type n) {
                it1_ -= n;
                return *this;
            }
            BOOST_UBLAS_INLINE
            difference_type operator - (const iterator1 &it) const {
                BOOST_UBLAS_CHECK (&(*this) () == &it (), external_logic ());
                return it1_ - it.it1_;
            }

            // Dereference
            BOOST_UBLAS_INLINE
            reference operator * () const {
                size_type i = index1 ();
                size_type j = index2 ();
                BOOST_UBLAS_CHECK (i < (*this) ().size1 (), bad_index ());
                BOOST_UBLAS_CHECK (j < (*this) ().size2 (), bad_index ());
#ifdef BOOST_UBLAS_OWN_BANDED
                size_type k = (std::max) (i, j);
                size_type l = (*this) ().lower () + j - i;
                if (k < (std::max) ((*this) ().size1 (), (*this) ().size2 ()) &&
                    l < (*this) ().lower () + 1 + (*this) ().upper ())
                    return *it1_;
#else
                size_type k = j;
                size_type l = (*this) ().upper () + i - j;
                if (k < (*this) ().size2 () &&
                    l < (*this) ().lower () + 1 + (*this) ().upper ())
                    return *it1_;
#endif
                return (*this) () (i, j);
            }

#ifndef BOOST_UBLAS_NO_NESTED_CLASS_RELATION
            BOOST_UBLAS_INLINE
#ifdef BOOST_UBLAS_MSVC_NESTED_CLASS_RELATION
            typename self_type::
#endif
            iterator2 begin () const {
                return (*this) ().find2 (1, index1 (), 0);
            }
            BOOST_UBLAS_INLINE
#ifdef BOOST_UBLAS_MSVC_NESTED_CLASS_RELATION
            typename self_type::
#endif
            iterator2 end () const {
                return (*this) ().find2 (1, index1 (), (*this) ().size2 ());
            }
            BOOST_UBLAS_INLINE
#ifdef BOOST_UBLAS_MSVC_NESTED_CLASS_RELATION
            typename self_type::
#endif
            reverse_iterator2 rbegin () const {
                return reverse_iterator2 (end ());
            }
            BOOST_UBLAS_INLINE
#ifdef BOOST_UBLAS_MSVC_NESTED_CLASS_RELATION
            typename self_type::
#endif
            reverse_iterator2 rend () const {
                return reverse_iterator2 (begin ());
            }
#endif

            // Indices
            BOOST_UBLAS_INLINE
            size_type index1 () const {
                return it1_.index1 ();
            }
            BOOST_UBLAS_INLINE
            size_type index2 () const {
                return it1_.index2 ();
            }

            // Assignment
            BOOST_UBLAS_INLINE
            iterator1 &operator = (const iterator1 &it) {
                container_reference<self_type>::assign (&it ());
                it1_ = it.it1_;
                return *this;
            }

            // Comparison
            BOOST_UBLAS_INLINE
            bool operator == (const iterator1 &it) const {
                BOOST_UBLAS_CHECK (&(*this) () == &it (), external_logic ());
                return it1_ == it.it1_;
            }
            BOOST_UBLAS_INLINE
            bool operator < (const iterator1 &it) const {
                BOOST_UBLAS_CHECK (&(*this) () == &it (), external_logic ());
                return it1_ < it.it1_;
            }

        private:
            subiterator1_type it1_;

            friend class const_iterator1;
        };
#endif

        BOOST_UBLAS_INLINE
        iterator1 begin1 () {
            return find1 (0, 0, 0);
        }
        BOOST_UBLAS_INLINE
        iterator1 end1 () {
            return find1 (0, size1 (), 0);
        }

#ifndef BOOST_UBLAS_USE_INDEXED_ITERATOR
        class const_iterator2:
            public container_const_reference<diagonal_vector_adaptor>,
            public random_access_iterator_base<packed_random_access_iterator_tag,
                                               const_iterator2, value_type> {
        public:
            typedef typename iterator_restrict_traits<typename const_subiterator2_type::iterator_category,
                                                      packed_random_access_iterator_tag>::iterator_category iterator_category;
            typedef typename const_subiterator2_type::value_type value_type;
            typedef typename const_subiterator2_type::difference_type difference_type;
            typedef typename const_subiterator2_type::reference reference;
            typedef typename const_subiterator2_type::pointer pointer;

            typedef const_iterator1 dual_iterator_type;
            typedef const_reverse_iterator1 dual_reverse_iterator_type;

            // Construction and destruction
            BOOST_UBLAS_INLINE
            const_iterator2 ():
                container_const_reference<self_type> (), it2_ () {}
            BOOST_UBLAS_INLINE
            const_iterator2 (const self_type &m, const const_subiterator2_type &it2):
                container_const_reference<self_type> (m), it2_ (it2) {}
            BOOST_UBLAS_INLINE
            const_iterator2 (const iterator2 &it):
                container_const_reference<self_type> (it ()), it2_ (it.it2_) {}

            // Arithmetic
            BOOST_UBLAS_INLINE
            const_iterator2 &operator ++ () {
                ++ it2_;
                return *this;
            }
            BOOST_UBLAS_INLINE
            const_iterator2 &operator -- () {
                -- it2_;
                return *this;
            }
            BOOST_UBLAS_INLINE
            const_iterator2 &operator += (difference_type n) {
                it2_ += n;
                return *this;
            }
            BOOST_UBLAS_INLINE
            const_iterator2 &operator -= (difference_type n) {
                it2_ -= n;
                return *this;
            }
            BOOST_UBLAS_INLINE
            difference_type operator - (const const_iterator2 &it) const {
                BOOST_UBLAS_CHECK (&(*this) () == &it (), external_logic ());
                return it2_ - it.it2_;
            }

            // Dereference
            BOOST_UBLAS_INLINE
            const_reference operator * () const {
                size_type i = index1 ();
                size_type j = index2 ();
                BOOST_UBLAS_CHECK (i < (*this) ().size1 (), bad_index ());
                BOOST_UBLAS_CHECK (j < (*this) ().size2 (), bad_index ());
#ifdef BOOST_UBLAS_OWN_BANDED
                size_type k = (std::max) (i, j);
                size_type l = (*this) ().lower () + j - i;
                if (k < (std::max) ((*this) ().size1 (), (*this) ().size2 ()) &&
                    l < (*this) ().lower () + 1 + (*this) ().upper ())
                    return *it2_;
#else
                size_type k = j;
                size_type l = (*this) ().upper () + i - j;
                if (k < (*this) ().size2 () &&
                    l < (*this) ().lower () + 1 + (*this) ().upper ())
                    return *it2_;
#endif
                return (*this) () (i, j);
            }

#ifndef BOOST_UBLAS_NO_NESTED_CLASS_RELATION
            BOOST_UBLAS_INLINE
#ifdef BOOST_UBLAS_MSVC_NESTED_CLASS_RELATION
            typename self_type::
#endif
            const_iterator1 begin () const {
                return (*this) ().find1 (1, 0, index2 ());
            }
            BOOST_UBLAS_INLINE
#ifdef BOOST_UBLAS_MSVC_NESTED_CLASS_RELATION
            typename self_type::
#endif
            const_iterator1 end () const {
                return (*this) ().find1 (1, (*this) ().size1 (), index2 ());
            }
            BOOST_UBLAS_INLINE
#ifdef BOOST_UBLAS_MSVC_NESTED_CLASS_RELATION
            typename self_type::
#endif
            const_reverse_iterator1 rbegin () const {
                return const_reverse_iterator1 (end ());
            }
            BOOST_UBLAS_INLINE
#ifdef BOOST_UBLAS_MSVC_NESTED_CLASS_RELATION
            typename self_type::
#endif
            const_reverse_iterator1 rend () const {
                return const_reverse_iterator1 (begin ());
            }
#endif

            // Indices
            BOOST_UBLAS_INLINE
            size_type index1 () const {
                return it2_.index ();
            }
            BOOST_UBLAS_INLINE
            size_type index2 () const {
                return it2_.index ();
            }

            // Assignment
            BOOST_UBLAS_INLINE
            const_iterator2 &operator = (const const_iterator2 &it) {
                container_const_reference<self_type>::assign (&it ());
                it2_ = it.it2_;
                return *this;
            }

            // Comparison
            BOOST_UBLAS_INLINE
            bool operator == (const const_iterator2 &it) const {
                BOOST_UBLAS_CHECK (&(*this) () == &it (), external_logic ());
                return it2_ == it.it2_;
            }
            BOOST_UBLAS_INLINE
            bool operator < (const const_iterator2 &it) const {
                BOOST_UBLAS_CHECK (&(*this) () == &it (), external_logic ());
                return it2_ < it.it2_;
            }

        private:
            const_subiterator2_type it2_;
        };
#endif

        BOOST_UBLAS_INLINE
        const_iterator2 begin2 () const {
            return find2 (0, 0, 0);
        }
        BOOST_UBLAS_INLINE
        const_iterator2 end2 () const {
            return find2 (0, 0, size2 ());
        }

#ifndef BOOST_UBLAS_USE_INDEXED_ITERATOR
        class iterator2:
            public container_reference<diagonal_vector_adaptor>,
            public random_access_iterator_base<typename iterator_restrict_traits<
                                                   typename subiterator2_type::iterator_category, packed_random_access_iterator_tag>::iterator_category,
                                               iterator2, value_type> {
        public:
            typedef typename subiterator2_type::value_type value_type;
            typedef typename subiterator2_type::difference_type difference_type;
            typedef typename subiterator2_type::reference reference;
            typedef typename subiterator2_type::pointer pointer;

            typedef iterator1 dual_iterator_type;
            typedef reverse_iterator1 dual_reverse_iterator_type;

            // Construction and destruction
            BOOST_UBLAS_INLINE
            iterator2 ():
                container_reference<self_type> (), it2_ () {}
            BOOST_UBLAS_INLINE
            iterator2 (self_type &m, const subiterator2_type &it2):
                container_reference<self_type> (m), it2_ (it2) {}

            // Arithmetic
            BOOST_UBLAS_INLINE
            iterator2 &operator ++ () {
                ++ it2_;
                return *this;
            }
            BOOST_UBLAS_INLINE
            iterator2 &operator -- () {
                -- it2_;
                return *this;
            }
            BOOST_UBLAS_INLINE
            iterator2 &operator += (difference_type n) {
                it2_ += n;
                return *this;
            }
            BOOST_UBLAS_INLINE
            iterator2 &operator -= (difference_type n) {
                it2_ -= n;
                return *this;
            }
            BOOST_UBLAS_INLINE
            difference_type operator - (const iterator2 &it) const {
                BOOST_UBLAS_CHECK (&(*this) () == &it (), external_logic ());
                return it2_ - it.it2_;
            }

            // Dereference
            BOOST_UBLAS_INLINE
            reference operator * () const {
                size_type i = index1 ();
                size_type j = index2 ();
                BOOST_UBLAS_CHECK (i < (*this) ().size1 (), bad_index ());
                BOOST_UBLAS_CHECK (j < (*this) ().size2 (), bad_index ());
#ifdef BOOST_UBLAS_OWN_BANDED
                size_type k = (std::max) (i, j);
                size_type l = (*this) ().lower () + j - i;
                if (k < (std::max) ((*this) ().size1 (), (*this) ().size2 ()) &&
                    l < (*this) ().lower () + 1 + (*this) ().upper ())
                    return *it2_;
#else
                size_type k = j;
                size_type l = (*this) ().upper () + i - j;
                if (k < (*this) ().size2 () &&
                    l < (*this) ().lower () + 1 + (*this) ().upper ())
                    return *it2_;
#endif
                return (*this) () (i, j);
            }

#ifndef BOOST_UBLAS_NO_NESTED_CLASS_RELATION
            BOOST_UBLAS_INLINE
#ifdef BOOST_UBLAS_MSVC_NESTED_CLASS_RELATION
            typename self_type::
#endif
            iterator1 begin () const {
                return (*this) ().find1 (1, 0, index2 ());
            }
            BOOST_UBLAS_INLINE
#ifdef BOOST_UBLAS_MSVC_NESTED_CLASS_RELATION
            typename self_type::
#endif
            iterator1 end () const {
                return (*this) ().find1 (1, (*this) ().size1 (), index2 ());
            }
            BOOST_UBLAS_INLINE
#ifdef BOOST_UBLAS_MSVC_NESTED_CLASS_RELATION
            typename self_type::
#endif
            reverse_iterator1 rbegin () const {
                return reverse_iterator1 (end ());
            }
            BOOST_UBLAS_INLINE
#ifdef BOOST_UBLAS_MSVC_NESTED_CLASS_RELATION
            typename self_type::
#endif
            reverse_iterator1 rend () const {
                return reverse_iterator1 (begin ());
            }
#endif

            // Indices
            BOOST_UBLAS_INLINE
            size_type index1 () const {
                return it2_.index1 ();
            }
            BOOST_UBLAS_INLINE
            size_type index2 () const {
                return it2_.index2 ();
            }

            // Assignment
            BOOST_UBLAS_INLINE
            iterator2 &operator = (const iterator2 &it) {
                container_reference<self_type>::assign (&it ());
                it2_ = it.it2_;
                return *this;
            }

            // Comparison
            BOOST_UBLAS_INLINE
            bool operator == (const iterator2 &it) const {
                BOOST_UBLAS_CHECK (&(*this) () == &it (), external_logic ());
                return it2_ == it.it2_;
            }
            BOOST_UBLAS_INLINE
            bool operator < (const iterator2 &it) const {
                BOOST_UBLAS_CHECK (&(*this) () == &it (), external_logic ());
                return it2_ < it.it2_;
            }

        private:
            subiterator2_type it2_;

            friend class const_iterator2;
        };
#endif

        BOOST_UBLAS_INLINE
        iterator2 begin2 () {
            return find2 (0, 0, 0);
        }
        BOOST_UBLAS_INLINE
        iterator2 end2 () {
            return find2 (0, 0, size2 ());
        }

        // Reverse iterators

        BOOST_UBLAS_INLINE
        const_reverse_iterator1 rbegin1 () const {
            return const_reverse_iterator1 (end1 ());
        }
        BOOST_UBLAS_INLINE
        const_reverse_iterator1 rend1 () const {
            return const_reverse_iterator1 (begin1 ());
        }

        BOOST_UBLAS_INLINE
        reverse_iterator1 rbegin1 () {
            return reverse_iterator1 (end1 ());
        }
        BOOST_UBLAS_INLINE
        reverse_iterator1 rend1 () {
            return reverse_iterator1 (begin1 ());
        }

        BOOST_UBLAS_INLINE
        const_reverse_iterator2 rbegin2 () const {
            return const_reverse_iterator2 (end2 ());
        }
        BOOST_UBLAS_INLINE
        const_reverse_iterator2 rend2 () const {
            return const_reverse_iterator2 (begin2 ());
        }

        BOOST_UBLAS_INLINE
        reverse_iterator2 rbegin2 () {
            return reverse_iterator2 (end2 ());
        }
        BOOST_UBLAS_INLINE
        reverse_iterator2 rend2 () {
            return reverse_iterator2 (begin2 ());
        }

    private:
        matrix_closure_type data_;
        size_type lower_;
        size_type upper_;
        typedef const value_type const_value_type;
        static const_value_type zero_;
    };

    template<class M>
    typename diagonal_vector_adaptor<M>::const_value_type diagonal_vector_adaptor<M>::zero_ = value_type/*zero*/();

    
    template<class M>
    BOOST_UBLAS_INLINE
    matrix_vector_slice<M> diag(M &data) {
            const typename M::size_type s = std::min(data.size1(),data.size2());
            return matrix_vector_slice<M>(data, slice(0,1,s), slice(0,1,s));
    };

    template<class M>
    BOOST_UBLAS_INLINE
    const matrix_vector_slice<const M> diag(const M &data) {
            const typename M::size_type s = std::min(data.size1(),data.size2());
            return matrix_vector_slice<const M>(data, slice(0,1,s), slice(0,1,s));
    };

    template<class V>
    BOOST_UBLAS_INLINE
    diagonal_vector_adaptor<V> diagm(V& data) {
            return diagonal_vector_adaptor<V>(data);
    };

    template<class V>
    BOOST_UBLAS_INLINE
    const diagonal_vector_adaptor<const V> diagm(const V& data) {
            return diagonal_vector_adaptor<const V>(data);
    };

}}}

#endif