# models.cuts¶

Objects that represent partitions of sets of nodes.

class pyphi.models.cuts.NullCut(indices, node_labels=None)

The cut that does nothing.

is_null

This is the only cut where is_null == True.

indices

Indices of the cut.

cut_matrix(n)

Return a matrix of zeros.

to_json()
class pyphi.models.cuts.Cut(from_nodes, to_nodes, node_labels=None)

Represents a unidirectional cut.

from_nodes

tuple[int] – Connections from this group of nodes to those in to_nodes are from_nodes.

to_nodes

tuple[int] – Connections to this group of nodes from those in from_nodes are from_nodes.

from_nodes
to_nodes
node_labels
indices

Indices of this cut.

cut_matrix(n)

Compute the cut matrix for this cut.

The cut matrix is a square matrix which represents connections severed by the cut.

Parameters: n (int) – The size of the network.

Example

>>> cut = Cut((1,), (2,))
>>> cut.cut_matrix(3)
array([[0., 0., 0.],
[0., 0., 1.],
[0., 0., 0.]])

to_json()

Return a JSON-serializable representation.

class pyphi.models.cuts.KCut(direction, partition, node_labels=None)

A cut that severs all connections between parts of a K-partition.

indices

Indices of this cut.

cut_matrix(n)

The matrix of connections that are severed by this cut.

to_json()
class pyphi.models.cuts.ActualCut(direction, partition, node_labels=None)

Represents an cut for a Transition.

indices

Indices of this cut.

class pyphi.models.cuts.Part

Represents one part of a Bipartition.

mechanism

tuple[int] – The nodes in the mechanism for this part.

purview

tuple[int] – The nodes in the mechanism for this part.

Example

When calculating $$\varphi$$ of a 3-node subsystem, we partition the system in the following way:

mechanism:  A,C    B
─── ✕ ───
purview:   B    A,C


This class represents one term in the above product.

Create new instance of Part(mechanism, purview)

to_json()

Return a JSON-serializable representation.

class pyphi.models.cuts.KPartition(*parts, node_labels=None)

A partition with an arbitrary number of parts.

parts
node_labels
mechanism

tuple[int] – The nodes of the mechanism in the partition.

purview

tuple[int] – The nodes of the purview in the partition.

normalize()

Normalize the order of parts in the partition.

to_json()
classmethod from_json(dct)
class pyphi.models.cuts.Bipartition(*parts, node_labels=None)

A bipartition of a mechanism and purview.

part0

Part – The first part of the partition.

part1

Part – The second part of the partition.

to_json()

Return a JSON-serializable representation.

classmethod from_json(dct)
node_labels
parts
class pyphi.models.cuts.Tripartition(*parts, node_labels=None)

A partition with three parts.

node_labels
parts