11#ifndef EIGEN_HOUSEHOLDER_H
12#define EIGEN_HOUSEHOLDER_H
17template<
int n>
struct decrement_size
41template<
typename Derived>
45 makeHouseholder(essentialPart, tau, beta);
63template<
typename Derived>
64template<
typename EssentialPart>
66 EssentialPart& essential,
68 RealScalar& beta)
const
73 EIGEN_STATIC_ASSERT_VECTOR_ONLY(EssentialPart)
76 RealScalar tailSqNorm = size()==1 ? RealScalar(0) : tail.squaredNorm();
78 const RealScalar tol = (std::numeric_limits<RealScalar>::min)();
80 if(tailSqNorm <= tol && numext::abs2(numext::imag(c0))<=tol)
83 beta = numext::real(c0);
88 beta = sqrt(numext::abs2(c0) + tailSqNorm);
89 if (numext::real(c0)>=RealScalar(0))
91 essential = tail / (c0 - beta);
92 tau =
conj((beta - c0) / beta);
111template<
typename Derived>
112template<
typename EssentialPart>
114 const EssentialPart& essential,
126 tmp.noalias() = essential.adjoint() * bottom;
128 this->row(0) -= tau * tmp;
129 bottom.noalias() -= tau * essential * tmp;
148template<
typename Derived>
149template<
typename EssentialPart>
151 const EssentialPart& essential,
163 tmp.noalias() = right * essential.conjugate();
165 this->col(0) -= tau * tmp;
166 right.noalias() -= tau * tmp * essential.transpose();
Expression of a fixed-size or dynamic-size block.
Definition: Block.h:105
internal::traits< Derived >::Scalar Scalar
Definition: DenseBase.h:66
A matrix or vector expression mapping an existing array of data.
Definition: Map.h:90
Base class for all dense matrices, vectors, and expressions.
Definition: MatrixBase.h:50
Expression of a fixed-size or dynamic-size sub-vector.
Definition: VectorBlock.h:60
Namespace containing all symbols from the Eigen library.
Definition: Core:287
const Eigen::CwiseUnaryOp< Eigen::internal::scalar_conjugate_op< typename Derived::Scalar >, const Derived > conj(const Eigen::ArrayBase< Derived > &x)
const int Dynamic
Definition: Constants.h:21