Representations and expansions of weighted pseudoinverse matrices, iterative methods, and problem regularization. II. singular weights (Q946780)

[For part I see ibid. 2008, No.~1, 47--73 (2008; Zbl 1155.65029).] The authors review the theory of weighted pseudoinversion and analyze the properties of weighted pseudoinverses and weighted normal pseudosolutions with singular (positive semidefinite) weights, and use these representations and expansions of weighted pseudoinverses to construct and study iterative methods and regularized problems to compute weighted pseudoinverses with singular weights and to solve constrained least-squares problems.