10. Iterative solver

In addition to offering basic linear algebra functions for dense tensors, Cytnx also includes an iterative solver for solving eigenvalue problems. By using the LinOp class, users can define a custom linear operator as a function or class, similar to scipy.LinearOperator.

This approach is more versatile than using the standard sparse storage format.

In the following section, we demonstrate how to define a custom linear operator using the LinOp class and how to solve the eigenvalue problem using the iterative solver.

• 10.1. LinOp class
  • 10.1.1. Inherit the LinOp class
  • 10.1.2. Example: sparse data structure with mapping function
  • 10.1.3. Prestore/preconstruct sparse elements
• 10.2. Lanczos solver
  • Lanczos_ER()