`topology` - the diarc graph data structure¶

This module contains the graph data structures used by diarc.

class topology.Topology¶

Storage container for describing the graph and diagram

vertices¶: An unordered list of all Vertex objects.

edges¶: An unordered list of all Edge objects

blocks¶: A dictionary of Block objects indexed by Block.index. The dictionary is generated every time it is requested. Only blocks with proper Block.index values are included.

bands¶: A dictionary of Band objects, listed by Band.altitude. Bands which have not been assigned altitudes are not reported. All bands that have an altitude (regardless of if they are being used (indicated by isUsed) are reported.

snaps¶: A dictionary of Snap objects, by snapkey. Snaps which have not been assigned an order are not reported. All snaps that have an order regardless of if they are being used (indicated by isUsed) are reported.

hide_disconnected_snaps¶

class topology.Vertex¶

A Vertex in a directional graph. A vertex can connect to multiple edges as either an input (source) or output (sink) to the edge. It is graphically represented by a Block object.

sources¶: Unordered list of outgoing connections (Source objects)

sinks¶: Unordered list of incomming connections. (Sink objects)

block¶: Block object for this Vertex. It is created when the vertex is instantiated, and cannot be reassigned.

release()¶: Removes this vertex from the topology. This additionally removes all its associated Connection and Block objects from the topology.

class topology.Edge¶

A directional multiple-input multiGple-output edge in the graph. Inputs (sources) and outputs (sinks) are linked to vertices. An edge is represented graphically by either 1 or 2 Band objects.

sources¶

sinks¶

posBand¶

negBand¶

release()¶

class topology.Connection¶

A base class for connecting a vertex to an edge, but without specifing the nature of the connection (input or output). Rather then using this class directly, Source or Sink objects should be used.

snap¶

edge¶

vertex¶

block¶

release()¶

class topology.Source(Connection)¶

A logical connection from a Vertex to an Edge. Graphically represented by a Snap object.

release()¶

class topology.Sink(Connection)¶

A logical connection from an Edge to a Vertex. Graphically represented by a Snap object.

release()¶

class topology.Block¶

Visual Representation of a Vertex Visual Parameters Index - Unique int value to determine order in which to draw blocks.

Lower values to the left, higher to the right. Indices do not necessarily need to be consecutive.

index¶: Defines the order in which blocks are arranged. This value is initially unset (defaults to None). For the block to be displayed as part of the graph, this value must be changed to a positive integer that is unique among blocks.

vertex¶: Returns the logical component (Vertex) for this relative object. The vertex is bound to this block, and cannot be changed.

emitter¶: Dictionary of Snaps that represent source connections for this block. Only snaps which have been assigned an order value are represented, since the order is used as the dictionary key. If hide_disconnected_snaps is set in the topology, only return snaps where isLinked() is true.

collector¶: Dictionary of Snap objects that represent sink connections for this block. Only snaps which have been assigned an order value are represented, since the order is used as the dictionary key. If hide_disconnected_snaps is set in the topology, only return snaps where isLinked() is true.

leftBlock¶: returns the block to the left, determined by block which has the next lowest index value.

rightBlock¶: returns the block to the right, determined by block which has the next highest index value.

class topology.Band¶

Visual Representation of an Edge. An Edge can have up to two Bands - one with positive altitude and one negative. Visual Parameters Rank - the Z drawing order (higher values closer to user) Altitude - the distance above or below the Block ribbon

altitude¶

rank¶

edge¶

emitters¶

collectors¶

isPositive¶

topBand¶

bottomBand¶

isUsed()¶

class diarc.topology.Vertex(topology)[source]¶

A Vertex in a directional graph. A vertex can connect to multiple edges as either an input (source) or output (sink) to the edge. It is graphically represented by a Block object.

Sources - outgoing connections to Edges Sinks - incomming connections from Edges

sources¶: Returns an unordered list of outgoing connections (Source objects) from this vertex.

sinks¶: Returns an unordered list of outgoing connections (Sink objects) from this vertex.

block¶: Returns the relative graphical object (Block) for this Vertex. The block cannot be changed

class diarc.topology.Edge(topology)[source]¶

A directional multiple-input multiGple-output edge in the graph. Inputs (sources) and outputs (sinks) are linked to vertices. An edge is represented graphically by either 1 or 2 Band objects.

Sources - inputs from vertices Sinks - outputs to vertices

release()[source]¶: Removes this edge from the topology

sources¶: returns list of all source connections to this edge

sinks¶: returns list of all sink connections from this edge

class diarc.topology.Connection(topology, vertex, edge)[source]¶

A base class for connecting a vertex to an edge, but without specifing the nature of the connection (input or output). Rather then using this class directly, Source or Sink objects should be used.

release()[source]¶: Removes this connection between a vertex and an edge from the topology. This does NOT release either the vertex or the edge objects, it simply removes this particular reference to them.

class diarc.topology.Source(topology, vertex, edge)[source]¶: A logical connection from a Vertex to an Edge. Graphically represented by a Snap object.

class diarc.topology.Sink(topology, vertex, edge)[source]¶: A logical connection from an Edge to a Vertex. Graphically represented by a Snap object.

class diarc.topology.Block(vertex)[source]¶

Visual Representation of a Vertex Visual Parameters Index - Unique int value to determine order in which to draw blocks.

Lower values to the left, higher to the right. Indices do not necessarily need to be consecutive.

vertex¶: Returns the logical component (Vertex) for this relative object. The vertex is bound to this block, and cannot be changed.

emitter¶: Dictionary of Snaps that represent source connections for this block. Only snaps which have been assigned an order value are represented, since the order is used as the dictionary key. If hide_disconnected_snaps is set in the topology, only return snaps where isLinked() is true.

collector¶: Dictionary of Snaps that represent sink connections for this block. Only snaps which have been assigned an order value are represented, since the order is used as the dictionary key. If hide_disconnected_snaps is set in the topology, only return snaps where isLinked() is true.

class diarc.topology.Band(edge, isPositive)[source]¶

Visual Representation of an Edge. An Edge can have up to two Bands - one with positive altitude and one negative. Visual Parameters Rank - the Z drawing order (higher values closer to user) Altitude - the distance above or below the Block ribbon

emitters¶: returns a list of source snaps that reach this band

collectors¶: returns list of sink snaps that reach this band

isUsed()[source]¶: returns true if this band is needed to represent connections on its edge, else false. This is determined by checking if any sources reach this band.

topBand¶: Returns the band with the next highest altitude, or None if either there is no band above this one or the block ribbon is above it. Bands for which isUsed() is false are skipped over.

bottomBand¶: Returns the band with the next lowest altitude, or None if either there is no band below this one or the block ribbon is below it. Bands for which isUsed() is false are skipped over.

class diarc.topology.Snap(connection)[source]¶

Visual Representation of a Source or Sink. Snaps are layedout horizontally inside of an Emitter or Collector of a Block. A Snap provides a mapping between a Source/Sink and one or two Bands associated with a single Edge. Visual Layout Paramters Order - 0-indexed order in which to draw snaps within an Emitter or Collector

snapkey()[source]¶: generates the snapkey for this snap

posBandLink¶: returns the positive band connection - if it exists. Just because a positive band link exists does not mean that it should be drawn. The check for if we should draw the connection happens at drawing time when we decide if we should be using positive or negative

negBandLink¶: returns the negative band connection - if it exists. See posBand for more details.

isLinked()[source]¶: returns true if this snap is connected to at least one sink, else false.

isUsed()[source]¶: returns true if topology.hide_disconnected_snaps is True and isLinked is True, or if topology.hide_disconnected_snaps is false. Otherwise, return true.

leftSnap¶: Returns the snap directly to the left of this snap within either an emitter or collector. Returns None if this is leftmost snap.

rightSnap¶: Returns the snap directly to the right of this snap within either an emitter or collector. Returns None if this is rightmost snap.

topology - the diarc graph data structure¶

`topology` - the diarc graph data structure¶