In this paper we present four parallel algorithms to compute any group of eigenvalues and eigenvectors of a Toeplitz-plus-Hankel matrix. These algorithms parallelize a method that combines the bisection technique with a fast root-finding procedure to obtain each eigenvalue. We design a parallel algorithm that applies a static distribution of the calculations among processors and three algorithms that use the farming technique to dynamically balance the load. All the algorithms have been implemented on a Multicomputer based on a network of transputers. We also present a study of the experimental performances and compare the different algorithms. The results obtained are in many cases very near to the maximum theoretical performances we can expect.
José M. Badía, Antonio M. Vidal