caa a22 4500 465774245 CHVBK 20180323111937.0 cr unu---uuuuu 170327e19901201xx s 000 0 eng 10.1007/BF02023055 doi (NATIONALLICENCE)springer-10.1007/BF02023055 Duff Iain Computer Science and Systems Division, Harwell Laboratory, OX11 0RA, Oxon, U.K. aut The solution of large-scale least-squares problems on supercomputers [Elektronische Daten] [Iain Duff] We discuss methods for solving medium to large-scale sparse least-squares problems on supercomputers, illustrating our remarks by experiments on the CRAY-2 supercomputer at Harwell. The method we are primarily concerned with is an augmented system approach which has the merit of both robustness and accuracy, in addition to a kernel operation that is just the solution of a symmetric indefinite system. We consider extensions to handle weighted and constrained problems, and include experiments on systems similar to those arising in the Karmarkar algorithm for linear programming. We indicate how recent improvements to the kernel software could greatly improve the performance of the least-squares code. J.C. Baltzer AG, Scientific Publishing Company, 1990 Annals of Operations Research Baltzer Science Publishers, Baarn/Kluwer Academic Publishers 22/1(1990-12-01), 241-252 0254-5330 22:1<241 1990 22 10479 https://doi.org/10.1007/BF02023055 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF02023055 text/html Onlinezugriff via DOI NATIONALLICENCE 100 1- Duff Iain Computer Science and Systems Division, Harwell Laboratory, OX11 0RA, Oxon, U.K aut NATIONALLICENCE 773 0- Annals of Operations Research Baltzer Science Publishers, Baarn/Kluwer Academic Publishers 22/1(1990-12-01), 241-252 0254-5330 22:1<241 1990 22 10479 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer