lar::util::details::FastMatrixOperations< T, DIM > Struct Template Reference

Provides "fast" matrix operations. More...

#include "FastMatrixMathHelper.h"

Inheritance diagram for lar::util::details::FastMatrixOperations< T, DIM >:

Public Types
using	Base_t = FastMatrixOperationsBase< T, DIM >
using	Data_t = typename Base_t::Data_t
using	Matrix_t = typename Base_t::Matrix_t
using	Vector_t = std::array< Data_t, Dim >

Static Public Member Functions
static Data_t	Determinant (Matrix_t const &mat)
	Computes the determinant of a matrix. More...
static Matrix_t	InvertMatrix (Matrix_t const &mat, Data_t det)
	Computes the determinant of a matrix, using the provided determinant. More...
static Matrix_t	InvertSymmetricMatrix (Matrix_t const &mat, Data_t det)
static Matrix_t	InvertMatrix (Matrix_t const &mat)
	Computes the determinant of a matrix. More...
static Matrix_t	InvertSymmetricMatrix (Matrix_t const &mat)
	Computes the determinant of a matrix. More...
static Vector_t	MatrixVectorProduct (Matrix_t const &mat, Vector_t const &vec)
	Returns the product of a square matrix times a column vector. More...
static constexpr Data_t	sqr (Data_t v)

Static Public Attributes
static constexpr unsigned int	Dim = DIM
	matrix dimensions More...

Detailed Description

template<typename T, unsigned int DIM>
struct lar::util::details::FastMatrixOperations< T, DIM >

Provides "fast" matrix operations.

Template Parameters

T	data type for the elements of the matrix
DIM	the dimension of the (square) matrix

Actually this class does nothing: specialize it!

Once the specialization is in place, this class offers:

constexpr unsigned int Dim = 2;
std::array<float, Dim*Dim> matrix;

float det = FastMatrixOperations<float, Dim>::Determinant();

std::array<float, Dim*Dim> inverse;

// generic inversion
inverse = FastMatrixOperations<float, Dim>::InvertMatrix(matrix);

// faster inversion if we already have the determinant
inverse = FastMatrixOperations<float, Dim>::InvertMatrix
  (matrix, det);

// faster inversion if we know the matrix is symmetric
inverse = FastMatrixOperations<float, Dim>::InvertSymmetricMatrix
  (matrix);

// even faster inversion if we also know the determinant already
inverse = FastMatrixOperations<float, Dim>::InvertSymmetricMatrix
  (matrix, det);

Note that the inversion functions do not have a defined policy for non-invertible matrices. If you need to check (and you usually do), compute the determinant first, and invert only if std::isnormal(det).

Definition at line 83 of file FastMatrixMathHelper.h.

Member Typedef Documentation

template<typename T , unsigned int DIM>

using lar::util::details::FastMatrixOperations< T, DIM >::Base_t = FastMatrixOperationsBase<T, DIM>

Definition at line 84 of file FastMatrixMathHelper.h.

template<typename T , unsigned int DIM>

using lar::util::details::FastMatrixOperations< T, DIM >::Data_t = typename Base_t::Data_t

Definition at line 85 of file FastMatrixMathHelper.h.

template<typename T , unsigned int DIM>

using lar::util::details::FastMatrixOperations< T, DIM >::Matrix_t = typename Base_t::Matrix_t

Definition at line 86 of file FastMatrixMathHelper.h.

template<typename T, unsigned int DIM>

using lar::util::details::FastMatrixOperationsBase< T, DIM >::Vector_t = std::array<Data_t, Dim>

inherited

Definition at line 39 of file FastMatrixMathHelper.h.

Member Function Documentation

template<typename T , unsigned int DIM>

static Data_t lar::util::details::FastMatrixOperations< T, DIM >::Determinant ( Matrix_t const &  mat )

static

Computes the determinant of a matrix.

template<typename T , unsigned int DIM>

static Matrix_t lar::util::details::FastMatrixOperations< T, DIM >::InvertMatrix ( Matrix_t const &  mat, Data_t  det  )

static

Computes the determinant of a matrix, using the provided determinant.

template<typename T , unsigned int DIM>

static Matrix_t lar::util::details::FastMatrixOperations< T, DIM >::InvertMatrix ( Matrix_t const &  mat )

inlinestatic

Computes the determinant of a matrix.

Definition at line 99 of file FastMatrixMathHelper.h.

        {
          return InvertMatrix(mat, Determinant(mat));
        }

template<typename T , unsigned int DIM>

static Matrix_t lar::util::details::FastMatrixOperations< T, DIM >::InvertSymmetricMatrix ( Matrix_t const &  mat, Data_t  det  )

static

Computes the determinant of a symmatric matrix, using the provided determinant

template<typename T , unsigned int DIM>

static Matrix_t lar::util::details::FastMatrixOperations< T, DIM >::InvertSymmetricMatrix ( Matrix_t const &  mat )

inlinestatic

Computes the determinant of a matrix.

Definition at line 105 of file FastMatrixMathHelper.h.

        {
          return InvertSymmetricMatrix(mat, Determinant(mat));
        }

template<typename T , unsigned int DIM>

auto lar::util::details::FastMatrixOperationsBase< T, DIM >::MatrixVectorProduct ( Matrix_t const &  mat, Vector_t const &  vec  )

staticinherited

Returns the product of a square matrix times a column vector.

Definition at line 360 of file FastMatrixMathHelper.h.

References lar::util::details::FastMatrixOperationsBase< T, DIM >::Dim, mat, and r.

{
  // not really fast, but there is probably not much to fasten...
  Vector_t res;
  Data_t const* mat_row = mat.data();
  for (size_t r = 0; r < Dim; ++r) {
    Data_t elem = Data_t(0);
    for (size_t c = 0; c < Dim; ++c)
      elem += *(mat_row++) * vec[c];
    res[r] = elem;
  } // for
  return res;
} // FastMatrixOperationsBase<>::MatrixVectorProduct()

template<typename T, unsigned int DIM>

static constexpr Data_t lar::util::details::FastMatrixOperationsBase< T, DIM >::sqr ( Data_t  v )

inlinestaticinherited

Definition at line 44 of file FastMatrixMathHelper.h.

{ return v * v; }

Member Data Documentation

template<typename T, unsigned int DIM>

constexpr unsigned int lar::util::details::FastMatrixOperationsBase< T, DIM >::Dim = DIM

staticinherited

matrix dimensions

Definition at line 36 of file FastMatrixMathHelper.h.

Referenced by lar::util::details::FastMatrixOperations< T, 2 >::InvertMatrix(), lar::util::details::FastMatrixOperations< T, 3 >::InvertMatrix(), lar::util::details::FastMatrixOperations< T, 4 >::InvertMatrix(), lar::util::details::FastMatrixOperations< T, 2 >::InvertSymmetricMatrix(), lar::util::details::FastMatrixOperations< T, 3 >::InvertSymmetricMatrix(), lar::util::details::FastMatrixOperations< T, 4 >::InvertSymmetricMatrix(), and lar::util::details::FastMatrixOperationsBase< T, DIM >::MatrixVectorProduct().

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

• lardata/v09_16_03/source/lardata/Utilities/FastMatrixMathHelper.h