Block reflector
From Wikipedia, the free encyclopedia
"A block reflector is an orthogonal, symmetric matrix that reverses a subspace whose dimension may be greater than one."
- see abstract here http://locus.siam.org/SINUM/volume-25/art_0725014.html
It is built out of many elementary reflectors.
It is also referred to as a triangular factor, and is a triangular matrix and they are used in the Householder transformation
[edit] LAPACK routines
Here are some of the LAPACK routines that apply to block reflectors
- "*larft" forms the triangular vector T of a block reflector H=I-VTVH.
- "*larzb" applies a block reflector or its transpose/conjugate transpose as returned by "*tzrzf" to a general matrix.
- "*larzt" forms the triangular vector T of a block reflector H=I-VTVH as returned by "*tzrzf".
- "*larfb" applies a block reflector or its transpose/conjugate transpose to a general rectangular matrix.
