On a QR-Like Algorithm for Some Structured Eigenvalue Problems
Alan D. George, Х. Д. Икрамов, Е. В. Матушкина, Weifang Tang · SIAM Journal on Matrix Analysis and Applications · 1995
In this paper, a QR-like algorithm, called the con-QR algorithm, for computing the Youla form of a general complex matrix is presented. The Youla form is an analog of the Schur form where unitary congruences instead of unitary similarities are employed. We introduce a set of invariants of a unitary congruence transformation which are called coneigenvalues, and discuss their condition. Finally, the practical value of the Youla form is discussed.