Characterization of the Oblique Projector with Application to Constrained Least Squares
arXiv:0809.4500 · doi:10.1016/j.laa.2009.05.025
Abstract
We provide a full characterization of the oblique projector in the general case where the range of and the null space of are not complementary subspaces. We discuss the new result in the context of constrained least squares minimization.
v1: 6 pages v2: 7 pages. Minor changes (formatting, references) in sections 1-2. Extra statement in Theorem 3.1. Substantial revision of section 4 v3: 7 pages. A minor change (more explicit formula for Ξ) in Corollary 4.2. Changed + to direct sum at the bottom of p.5 v4: 7 pages. Removed typo in eq. (17) which was present in v2 and v3