Refactor `TensorNetwork` type; add `NormNetwork` struct. by jack-dunham · Pull Request #119 · ITensor/ITensorNetworksNext.jl

jack-dunham · 2026-06-08T18:25:27Z

This PR refactors the TensorNetwork data type to include a reverse index map, and to be stricter about it's construction and how it's tensors can be set.

This PR also adds NormNetwork type, as a wrapper around a TensorNetwork, to represent the norm of a tensor network.

Introduce `BeliefPropagationProblem` wrapper to hold the cache and the error `diff` field. Also simplifies some kwargs wrangling.

…be set from another cache

Also includes some fixes to the way `TensorNetwork` types are constructed based on index structure.

for more information, see https://pre-commit.ci

…instead of trying to operate on existing graphs The reason for this is: - One only cares about the edges of the input graph - A simple graph cannot be used as it "forgets" its edge names resulting in recursion - As shown with `TensorNetwork`, removing edges may not always be defined.

…s from an array.

…a order-0 array

This was caused by the change to the `cache` being backed by a directed graph.

…_message_environment`.

JoeyT1994 and others added 30 commits January 6, 2026 09:55

Working BP Commit

b4ae4d7

BP Code

d77d063

Express BP in terms of SweepIterator interface

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Introduce `BeliefPropagationProblem` wrapper to hold the cache and the error `diff` field. Also simplifies some kwargs wrangling.

Add method for setmessages! that allows messages from one cache to …

fe44b80

…be set from another cache

Network is now passed to forest_cover_edge_sequence directly.

3ce0898

test file formatting

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Add DataGraphsPartitionedGraphsExt glue for TensorNetwork type

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Also includes some fixes to the way `TensorNetwork` types are constructed based on index structure.

Make abstract tensor network interface more generic.

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BP Caching overhauls

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Remove dead deps

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Fix merge

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Fix type inference in TensorNetwork construction

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[pre-commit.ci] auto fixes from pre-commit.com hooks

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for more information, see https://pre-commit.ci

Remove ITensorBase dep

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[LazyNamedDimsArrays] Fix parenttype method

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BP Cache now uses new DataGraphsinterface

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Adjust default_message to take a message type as its first argument

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Remove unnecessary code and fix ambiguities in AbstractTensorNetwork

c43884e

TensorNetwork type now uses new DataGraphs interface

dd6f645

Sweeping algorithms based on AlgorithmsInterface.jl (#30)

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Upgrade to NamedDimsArrays.jl v0.11 (#38)

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[LazyNamedDimsArrays] New symnameddims method that pulls out indice…

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…s from an array.

The function region_scalar should now return a scalar, rather than …

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…a order-0 array

Fix double counting in edge_scalars function

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This was caused by the change to the `cache` being backed by a directed graph.

Minor code formatting

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Expressed belief propagation in terms of AlgorithmsInterface

4461967

Fixes to TensorNetwork construction from tensor list

d68860a

Minor simplifications to contract_network interface.

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Merge branch 'main' into bp

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