mirror/eigen
2
0
Fork 0
mirror of https://gitlab.com/libeigen/eigen.git synced 2024-12-09 07:00:27 +08:00
Code Issues Packages Projects Releases Wiki Activity

Document on MatrixExponential::ScalingOp

Browse Source
This commit is contained in:
Chen-Pang He 2013-07-21 00:18:19 +08:00
parent ede27f5780
commit 3d94ed9fa0
1 changed files with 17 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

20
unsupported/Eigen/src/MatrixFunctions/MatrixExponential.h
View File

@ -126,6 +126,7 @@ class MatrixExponential : internal::noncopyable
*/ */
void computeUV(long double); void computeUV(long double);
struct ScalingOp;
typedef typename internal::traits<MatrixType>::Scalar Scalar; typedef typename internal::traits<MatrixType>::Scalar Scalar;
typedef typename NumTraits<Scalar>::Real RealScalar; typedef typename NumTraits<Scalar>::Real RealScalar;
typedef typename std::complex<RealScalar> ComplexScalar; typedef typename std::complex<RealScalar> ComplexScalar;
@ -153,22 +154,35 @@ class MatrixExponential : internal::noncopyable
/** \brief L1 norm of m_M. */ /** \brief L1 norm of m_M. */
RealScalar m_l1norm; RealScalar m_l1norm;
/** \brief Scaling operator. */
struct ScalingOp;
}; };
/** \brief Scaling operator.
*
* This struct is used by CwiseUnaryOp to scale a matrix by \f$ 2^{-s} \f$.
*/
template <typename MatrixType> template <typename MatrixType>
struct MatrixExponential<MatrixType>::ScalingOp struct MatrixExponential<MatrixType>::ScalingOp
{ {
/** \brief Constructor.
*
* \param[in] squarings The integer \f$ s \f$ in this document.
*/
ScalingOp(int squarings) : m_squarings(squarings) { } ScalingOp(int squarings) : m_squarings(squarings) { }
/** \brief Scale a matrix coefficient.
*
* \param[in,out] x The scalar to be scaled, becoming \f$ 2^{-s} x \f$.
*/
inline const RealScalar operator() (const RealScalar& x) const inline const RealScalar operator() (const RealScalar& x) const
{ {
using std::ldexp; using std::ldexp;
return ldexp(x, -m_squarings); return ldexp(x, -m_squarings);
} }
/** \brief Scale a matrix coefficient.
*
* \param[in,out] x The scalar to be scaled, becoming \f$ 2^{-s} x \f$.
*/
inline const ComplexScalar operator() (const ComplexScalar& x) const inline const ComplexScalar operator() (const ComplexScalar& x) const
{ {
using std::ldexp; using std::ldexp;