Vasileios Kalantzis  Vasileios Kalantzis photo         

contact information

Research Staff Member
IBM Research USA, Thomas J. Watson Research Center


Professional Associations

Professional Associations:  ACM  |  Society for Industrial and Applied Mathematics

Schurcheb (MPI/C++)

Schurcheb is a MPI-based parallel library for computing partial spectral factorizations of matrix pencils via Chebyshev approximation. The library returns those eigenvalues (and corresponding eigenvectors) of symmetric matrix pencils that lie within a target interval.

Github repository


ParGeMSLR is a MPI-based parallel library for the solution of sparse linear systems. It is based on algebraic domain decomposition and combines ideas from block-Jacobi preconditioners and low-rank corrections.

Github repository

Cucheb (CUDA)

The Cucheb library is a CUDA implementation of the filtered Lanczos procedure for the solution of sparse Hermitian eigenvalue problems on NVIDIA GPUs.

Github repository

EigenRec (Fortran90/MPI)

The EigenRec library is a Fortran 90 implementation of a Lanczos-based, latent factor framework for Top-N recommendations. EigenRec is designed for distributed memory computing environments.

Github repository

PP-BCG (Fortran90/MPI)

The Parallel Projection Block Conjugate Gradient (PP-BCG) library is a Fortran 90 implementation of an accelerated block Conjugate Gradient scheme for the solution of SPD dense linear systems with multiple right-hand sides. PP-BCG targets distributed memory computing environments and has been successfully tested on up to four BG/Q racks (65,536 cores).

Source files

TeraPCA (C++)

TeraPCA is a multithreaded C++ software suite based on Intel's MKL library (or any other BLAS and/or LAPACK distribution) that aims on computing the leading Principal Components of large-scale datasets that can not fully reside on the system memory. TeraPCA features no dependencies to external libraries and combines the robustness of subspace iteration with the power of randomization.

Github repository