Could you please give an example about it in Eigen or Armadillo format? It's hard for me to understand how to add shifts_f and access eigenvalues. Thanks a lot.

In this work, we present a computational method for solving eigenvalue problems of fourth-order ordinary differential equations which based on the use of Chebychev method. The efficiency of the method ...

In this paper we present a new subspace iteration for calculating a cluster of k exterior eigenvalues of a given symmetric matrix,. Other names for such eigenvalues are “peripheral eigenvalues” and ...