xerus

The xerus library is a general purpose library for numerical calculations with higher order tensors, Tensor-Train Decompositions / Matrix Product States and general Tensor Networks. The focus of development was the simple usability and adaptibility to any setting that requires higher order tensors or decompositions thereof.

The key features include:

• Modern code and concepts incorporating many features of the C++11 standard.
• Full python bindings with very similar syntax for easy transitions from and to c++.
• Calculation with tensors of arbitrary orders using an intuitive Einstein-like notation A(i,j) = B(i,k,l) * C(k,j,l);.
• Full implementation of the Tensor-Train decompositions (MPS) with all neccessary capabilities (including Algorithms like ALS, ADF and CG).
• Lazy evaluation of (multiple) tensor contractions featuring heuristics to automatically find efficient contraction orders.
• Direct integration of the blas and lapack, as high performance linear algebra backends.
• Fast sparse tensor calculation by usage of the suiteSparse sparse matrix capabilities.
• Capabilites to handle arbitrary Tensor Networks.

https://libxerus.org/ 

https://git.hemio.de/xerus/xerus