Package with data structures and functions for manipulating tensor networks
Author JuliaQX
4 Stars
Updated Last
1 Year Ago
Started In
February 2021


Stable Dev Build Status Coverage

QXTns is a Julia package with data structures and utilities for manipulating tensor networks. As well as generic tensor network data structure, it also contains specific data structures for handling tensor networks derived from quantum circuits. It was developed as part of the QuantEx project, one of the individual software projects of WP8 of PRACE 6IP.

It uses some features from ITensors and NDTensors for representing tensors and indices and performing contractions.


QXTns is a Julia package and can be installed using Julia's inbuilt package manager from the Julia REPL using.

import Pkg

To ensure everything is working, the unittests can be run using

import Pkg; Pkg.test()

Example usage

An example of creating a simple tensor network and contracting.

using QXTns

tn = TensorNetwork()

a, b, c, d = Index(2), Index(3), Index(5), Index(4)

# add a 2x3x5 rank tensor
push!(tn, [a, b, c], rand(2, 3, 5))
# add a 5x4 matrix
push!(tn, [c, d], rand(5, 4))

# contract network

# number of tensors after contraction
@show length(tn)

# resulting tensor has dimensions should have dimensions 2x3x4
@show size(first(tn))


Contributions from users are welcome and we encourage users to open issues and submit merge/pull requests for any problems or feature requests they have. The CONTRIBUTING.md has further details of the contribution guidelines.

Building documentation

QXTns.jl uses Documenter.jl to generate documentation. To build the documentation locally run the following from the root folder.

The first time it is will be necessary to instantiate the environment to install dependencies

julia --project=docs/ -e 'using Pkg; Pkg.develop(PackageSpec(path=pwd())); Pkg.instantiate()'

and then to build the documentation

julia --project=docs/ docs/make.jl

The generated document will be in the docs/build folder. To serve these locally one can use the LiveServer package as

julia --project -e 'import Pkg; Pkg.add("LiveServer");
julia --project -e  'using LiveServer; serve(dir="docs/build")'

Or with python3 using from the docs/build folder using

python3 -m http.server

The generated documentation should now be viewable locally in a browser at http://localhost:8000.

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