Wolfram Language Paclet Repository
Community-contributed installable additions to the Wolfram Language
Wolfram`TensorNetworks`
TensorNetworkQ  |
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returns only when the head of is and its tensors, hyperedges, and output specification are internally consistent; any other head yields .
tn
▪
Internal consistency requires three conditions on a [, , ] expression: the length of must equal the length of ; each tensor's rank must equal the length of its hyperedge list; and every occurrence of a shared index must report the same dimension.
tensors
hyperedges
output
tensors
hyperedges
▪
▪
caches the validation result via : an unvalidated […] expression is checked once on first evaluation; if the check passes, marks the expression and freezes its argument slots, so subsequent calls short-circuit without re-validating.
System`Private`HoldValidQ
System`Private`HoldSetValid
System`Private`HoldSetNoEntry
▪
Property dispatch on a object is guarded by : only evaluates when satisfies , so an invalid […] expression is left unevaluated rather than returning a wrong answer.
tn["Property"]
tn
Examples
(11)
Basic Examples
(1)
Test whether an expression is a valid tensor network:
In[1]:=
 | TensorNetworkQ |
 | TensorNetwork |
Out[1]=
True
A network produced by RandomTensorNetwork is valid by construction:
In[2]:=
SeedRandom[42];mps=
["MPS"[4,2,2]];
[mps]
 | RandomTensorNetwork |
| TensorNetworkQ |
Out[2]=
True
Anything whose head is not TensorNetwork is rejected:
In[3]:=
| TensorNetworkQ |
Out[3]=
False
Scope
(6)
Applications
(1)
Properties & Relations
(3)
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