This two-volume work presents a systematic theoretical and computational
study of several types of generalizations of separable matrices. The
main attention is paid to fast algorithms (many of linear complexity)
for matrices in semiseparable, quasiseparable, band and companion form.
The work is focused on algorithms of multiplication, inversion and
description of eigenstructure and includes a large number of
illustrative examples throughout the different chapters. The first
volume consists of four parts. The first part is of a mainly theoretical
character introducing and studying the quasiseparable and semiseparable
representations of matrices and minimal rank completion problems. Three
further completions are treated in the second part. The first
applications of the quasiseparable and semiseparable structure are
included in the third part where the interplay between the
quasiseparable structure and discrete time varying linear systems with
boundary conditions play an essential role. The fourth part contains
factorization and inversion fast algorithms for matrices via
quasiseparable and semiseparable structure. The work is based mostly on
results obtained by the authors and their coauthors. Due to its many
significant applications and the accessible style the text will be
useful to engineers, scientists, numerical analysts, computer scientists
and mathematicians alike.