A NEW PARALLEL CHASING ALGORITHM FOR TRANSFORMING ARROWHEAD MATRICES TO TRIDIAGONAL FORM

Rutishauser, Gragg and Harrod and finally H.Y. Zha used the same class of chasing algorithms for transforming arrowhead matrices to tridiago nal form. Using a graphical theoretical approach, we propose a new cha sing algorithm. Although this algorithm has the same sequential comput ational complexity and backward error properties as the old algorithms , it is better suited for a pipelined approach. The parallel algorithm for this new chasing method is described, with performance results on the Paragon and nCUBE. Comparison results between the old and the new algorithms are also presented.