pitts 0.9.6

Abstract

PITTS--Parallel Iterative Tensor-Train Solvers--is a small header-only C++20 library for numerical algorithms with low-rank tensor approximations in tensor train form (TT format, see 2 and 3). Algorithms are parallelized for multi-core CPU clusters using OpenMP and MPI. Currently provides a fast TT-SVD implementation (algorithm to compress a dense tensor in the TT format), and methods for solving linear systems (symmetric and non-symmetric) in tensor-train format (TT-GMRES 4, TT-MALS 5, TT-AMEn 6). Bindings to other languages / libraries: * Python: complete functionality using pybind11 with numpy-compatible interface * ITensor (C++): conversion to/from MPS and MPO * Julia (JlCxx): basic data types and TSQR algorithm