`cotengra.pathfinders.path_compressed_greedy`¶

Greedy contraction tree finders.

Module Contents¶

Classes¶

`GreedyCompressed`	A greedy contraction path finder that takes into account the effect of
`GreedySpan`	A contraction path optimizer that greedily generates spanning trees out

Functions¶

`trial_greedy`(inputs, output, size_dict[, ...])
`_binary_combine`(func, x, y)
`greedy_compressed`(inputs, output, size_dict[, ...])
`trial_greedy_compressed`(inputs, output, size_dict, ...)
`greedy_span`(inputs, output, size_dict[, memory_limit])
`trial_greedy_span`(inputs, output, size_dict, **kwargs)

Attributes¶

`ssa_greedy_optimize`
`_allowed_perms`

cotengra.pathfinders.path_compressed_greedy.ssa_greedy_optimize¶

cotengra.pathfinders.path_compressed_greedy.trial_greedy(inputs, output, size_dict, random_strength=0.0, temperature=0.0, costmod=1.0)[source]¶

cotengra.pathfinders.path_compressed_greedy._binary_combine(func, x, y)[source]¶

class cotengra.pathfinders.path_compressed_greedy.GreedyCompressed(chi, coeff_size_compressed=1.0, coeff_size=0.0, coeff_size_inputs=0.0, score_size_inputs='max', coeff_subgraph=0.0, score_subgraph='sum', coeff_centrality=0.0, centrality_combine='max', score_centrality='diff', temperature=0.0, score_perm='', early_terminate_size=None, seed=None)[source]¶

A greedy contraction path finder that takes into account the effect of compression, and can also make use of subgraph size and centrality.

Parameters:

chi (int) – The maximum bond size between nodes to compress to.
coeff_size_compressed (float, optional) – When assessing contractions, how to weight the size of the output tensor, post compression.
coeff_size (float, optional) – When assessing contractions, how to weight the size of the output tenor, pre compression.
coeff_size_inputs (float, optional) – When assessing contractions, how to weight the maximum size of the inputs tensors.
score_size_inputs ({'sum', 'mean', 'max', 'min', 'diff'}, optional) – When assessing contractions, how to score the combination of the two input tensor sizes.
coeff_subgraph_size (float, optional) – When assessing contractions, how to weight the total subgraph size corresponding to the inputs tensors.
score_subgraph_size ({'sum', 'mean', 'max', 'min', 'diff'}, optional) – When assessing contractions, how to score the combination of the two input subgraph sizes.
coeff_centrality (float, optional) – When assessing contractions, how to weight the combined centrality of the inputs tensors.
centrality_combine ({'sum', 'mean', 'max', 'min'}, optional) – When performing the contraction, how to combine the two input tensor centralities to produce a new one.
score_centrality ({'sum', 'mean', 'max', 'min', 'diff'}, optional) – When assessing contractions, how to score the combination of the two input tensor centralities.
temperature (float, optional) – A noise level to apply to the scores when choosing nodes to expand to.

_score(i1, i2)[source]¶

get_ssa_path(inputs, output, size_dict)[source]¶

search(inputs, output, size_dict)[source]¶

__call__(inputs, output, size_dict, memory_limit=None)[source]¶

cotengra.pathfinders.path_compressed_greedy.greedy_compressed(inputs, output, size_dict, memory_limit=None, **kwargs)[source]¶

cotengra.pathfinders.path_compressed_greedy.trial_greedy_compressed(inputs, output, size_dict, **kwargs)[source]¶

class cotengra.pathfinders.path_compressed_greedy.GreedySpan(start='max', coeff_connectivity=1.0, coeff_ndim=1.0, coeff_distance=-1.0, coeff_next_centrality=0.0, weight_bonds=True, temperature=0.0, score_perm='CNDLTI', distance_p=1, distance_steal='abs', seed=None)[source]¶

A contraction path optimizer that greedily generates spanning trees out of particular nodes, suitable for e.g. compressed contraction paths.