Enhancement of the Subspace Iteration Method : 1st Report, Basic Study

Abstract

In this report, two procedures to enhance the subspace iteration method are presented. One is a method of multiple condensation toward lower eigenvectors during one step of the iteration (Fig.3). This method is called the multi-condensation subspace iteration method. The other is a strategy for the selection of starting vectors in the origin-shifted subspace iteration method (Fig.5). Starting vectors are set to have desirable qualities.