banded.h

来自「高效的c++科学算法库」· C头文件 代码 · 共 127 行

#ifndef SL_MATRIX_STRUCTURES_BANDED_BANDED_H
#define SL_MATRIX_STRUCTURES_BANDED_BANDED_H

/*
 ******************************
 * Scientific Library (GNU Public Licence)
 *
 * Author: Laurent Deniau, [e-mail]
 *
 * $Id: banded.h,v 1.1 1998/11/05 12:48:36 paubert Exp $
 *
 * Suggestions: [e-mail]
 * Bugs:   [e-mail]
 *
 * For more information, please see the sl++ Home Page:
 * http://wwwinfo.cern.ch/~ldeniau/sl.html
 *
 ******************************
 */

#ifndef SL_MATRIX_STRUCTURES_BANDED_H
#error <sl/matrix/structures/banded/banded.h> must be included via <sl/matrix/structures/banded.h>
#endif

#ifdef HAVE_NAMESPACE
namespace sl 
{
#endif

// Banded matrix structure

//
// LB=1, UB=2
// [1 2 3 .]
// [4 5 6 7]
// [. 8 9 0]
// [. . 1 2]
//


// Default template is equivalent to Diagonal matrix

    template <Index LB, Index UB>
        class BandedIterator;
    
    template <Index LB, Index UB>
        class Banded : public MatrixStructure {
            
            
            public:
            
            typedef BandedIterator<LB,UB> iterator_t;
            
            Index lbands () const { return LB; }
            Index ubands () const { return UB; }
            Index nbands () const { return LB+UB+1; }
            
            size_t size () const { return (my_n<=my_p+LB ? my_n : my_p+LB)*nbands(); }

            Index  rows () const { return my_n; }
            Index  cols () const { return my_p; }

            Index firstInRow (Index const i) const { return i<=LB ? MinIndex : i-LB; }
            Index firstInCol (Index const j) const { return j<=UB ? MinIndex : j-UB; }
            Index lastInRow  (Index const i) const { return i+UB>=my_p ? my_p : i+UB; }
            Index lastInCol  (Index const j) const { return j+LB>=my_n ? my_n : j+LB; }

            static Bool isRowMajor () { return true; }


              // map(MinIndex,MinIndex)
            ptrdiff_t offset () const { return (UB+1)*MinIndex; }


            Banded () : my_n (0), my_p (0) { }

            Banded (Index const n) : my_n (n), my_p (n)
            {
                assert( n>LB );
                assert( n>UB );
            }

            Banded (Index const n, Index const p) : my_n (n), my_p (p)
            {
                assert( n==p );
                assert( n>LB );
                assert( n>UB );
            }

              // WARNING: Do NOT declare the copy constructor !
  

            void
            resize (Index const n, Index const p) {
                my_n = n; my_p = p;
            }

            template <typename T_value>
            T_value&
            get (T_value* const data, Index const i, Index const j) {
                return i<=LB+j && j<=UB+i ? data[map(i,j)] : zero_ref<T_value>();
            }

            template <typename T_value>
            T_value
            get (T_value const* const data, Index const i, Index const j) const {
                return i<=LB+j && j<=UB+i ? data[map(i,j)] : T_value();
            }


            private:

            Index
            map (Index const i, Index const j) const {
                return i*nbands()+j-i;
            }

            Index my_n, my_p;
        };


#ifdef HAVE_NAMESPACE
}
#endif 

#endif // SL_MATRIX_STRUCTURES_BANDED_BANDED_H