symmetric.h

来自「高效的c++科学算法库」· C头文件 代码 · 共 115 行

#ifndef SL_MATRIX_STRUCTURES_SYMMETRIC_SYMMETRIC_H
#define SL_MATRIX_STRUCTURES_SYMMETRIC_SYMMETRIC_H

/*
 ******************************
 * Scientific Library (GNU Public Licence)
 *
 * Author: Laurent Deniau, [e-mail]
 *
 * $Id: symmetric.h,v 1.1 1998/11/05 12:48:39 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_SYMMETRIC_H
#error <sl/matrix/structures/symmetric/symmetric.h> must be included via <sl/matrix/structures/symmetric.h>
#endif

#ifdef HAVE_NAMESPACE
namespace sl 
{
#endif

/*
  WARNING:
  These classes MUST use the default copy constructor
*/
  

// Symmetric matrix structure

//
// [1 2 4]
// [2 3 5]
// [4 5 6]
//


    class Symmetric : public MatrixStructure {


      public:

        typedef SymmetricIterator iterator_t;

        size_t size () const { return my_n*(my_n+1)/2; }

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

        Index firstInRow (Index const i) const { return MinIndex; }
        Index firstInCol (Index const j) const { return j; }
        Index lastInRow  (Index const i) const { return i; }
        Index lastInCol  (Index const j) const { return my_n; }

        static Bool isRowMajor () { return true; }


          // map(MinIndex,MinIndex)
        ptrdiff_t offset () const { return MinIndex; }


        Symmetric () : my_n (0) { }

        Symmetric (Index const n) : my_n (n) { }

        Symmetric (Index const n, Index const p) : my_n (n) {
            assert ( p == cols() );
        }
        
          // WARNING: Do NOT declare the copy constructor !
  
        void
            resize (Index const n, Index const p) {
            my_n = n;
            assert ( p == cols() );
        }

        template <typename T_value>
            T_value&
            get (T_value* const data, Index const i, Index const j) {
            return data[map(i,j)];
        }

        template <typename T_value>
            T_value
            get (T_value const* const data, Index const i, Index const j) const {
            return data[map(i,j)];
        }


      private:

        Index
            map (Index const i, Index const j) const {
            return j<=i ? (i-MinIndex)*(i-MinIndex+1)/2+j : 
                (j-MinIndex)*(j-MinIndex+1)/2+i;
        }

        Index my_n;
    };


#ifdef HAVE_NAMESPACE
}
#endif 

#endif // SL_MATRIX_STRUCTURES_SYMMETRIC_SYMMETRIC_H