LowerTriangular< N, value > Class Template Reference [Small Matrix Classes]

A symmetric matrix stored in lower triangular form. More...

#include <ocean/eagle/Matrix.hpp>

Inherits @593::Vector< value, N *(N+1)/2 >.

List of all members.

Classes

• struct TriangularIndex

Public Types

• enum { rows = N }
• enum { columns = N, cols = N }
• enum { SIZE = Vector_t::SIZE }

  The number of value elements, i.e. N*(N+1)/2.

  
  

• enum { MEMSIZE = sizeof(Base_t) / sizeof(value) }

  The number of value elements occupied in memory due to alignment.

  
  

• typedef Vector< value, N *(N+1)/2 > Base_t

  The (vectorial) base class.
  

• typedef Base_t::Vector_t Vector_t

  The compatible vector class.
  

Public Member Functions

• LowerTriangular (const LowerTriangular &LT, const LowerTriangular &RT, const Operator<'-'> &A)

  Computational constructor for adding two types.
  

• LowerTriangular (const LowerTriangular &LT, const LowerTriangular &RT, const Operator<'+'> &A)

  Computational constructor for adding two types.
  

• LowerTriangular (const LowerTriangular &LT, const value &v, const Operator<'*'> &M)

  Computational constructor for scalar multiplication.
  

• template<class T > LowerTriangular (const LowerTriangular< N, T > &LT)

  Construct from symmetric matrix of same size but different type.
  

• template<class T > LowerTriangular (const Vector< T, N *(N+1)/2 > &V)

  Construct symmetric matrix from compatible vector of possibly different type.
  

• LowerTriangular (const LowerTriangular &LT)

  Copy constructor.
  

• LowerTriangular ()

  Constructor, does not initialize anything.
  

• const value & operator() (int row, int column) const

  readonly Element access
  

• value & operator() (int row, int column)

  read/write Element access
  

• const LowerTriangular< N-1,
  value > & submatrix () const

  Due to the special layout of the LowerTriangular matrix class, retrieving a reference to the lower dimensional submatrix is a no-cost operation.
  

• LowerTriangular< N-1, value > & submatrix ()

  Due to the special layout of the LowerTriangular matrix class, retrieving a writeable reference to the lower dimensional submatrix is a possible operation and without runtime costs.
  

Static Public Member Functions

• static int mem_index (int row, int column)

  Retrieve the linear index from row/column indices.
  

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Detailed Description

template<int N, class value>
class LowerTriangular< N, value >

A symmetric matrix stored in lower triangular form.

For a 3x3 symmetric matrix (six independent components) we get the following layout:

0 1 3
1 2 4
3 4 5

and for a 4x4 symmetric matrix with ten components we get:

0 1 3 6
1 2 4 7
3 4 5 8
6 7 8 9

This layout ensures that the upper left submatrix of lower dimension is always contained in higher dimensional matrices. I.e. a matrix of type LowerTriangular<N> may always be casted to a matrix of type LowerTriangular<N-n> with n<N.

Examples:

Matrix.cpp.

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The documentation for this class was generated from the following file:

• ocean/eagle/Matrix.hpp