PETER HALL, SPIRIDON PENEV, GE RARD KERKYACHARIAN and DOMINIQUE PICARD Centre for Mathematics and its Applications, Australian National University, Canberra, ACT 0200, Australia School of Mathematics, University of NSW, Sydney, NSW 2052, Australia Faculte Mathematiques et Informatiques, Universite de Picardie, 33 rue Saint-Leu, 80039 Amiens Cedex 01, France DeÂpartement de Mathematiques, Uni...

The use of the row block projection method (block Cimmino) for solving nonsymmetric linear system Ax = b gives rise to a symmetric positive definite system G x = g, where B is the sum of orthogonal projection matrices Pi = Ai(ATAi)-'AT, and where the Ar's are block rows of A. In this paper we present an efficient implementation of the cgT method for solving the derived symmetric positive defini...