## FETA (Framework for Evolving Topology Analysis) software## Model File FormatFETA models are defined by this file format. The model comes in two parts, an outer model and an inner model. The outer model describes what operation occurs on the network. The inner model describes a probability model for the entity on which this operation occurs. Currently the outer model operations can be: Connect an edge from an existing node to a new node Connect an edge between two existing nodes
These are matched to two inner models: The **new node model**assigns probabilities to a node which will connect to the newest node in the network.The **inner edge model**assigns probabilities to nodes, pairs of which will be connected.
Each line in the file begins either
## Outer model file formatA line beginning n specifies the outer model for adding new nodes. The next lines are a probability distribution for the number of existing nodes the new node connects to. This line MUST be present.
A line beginning e describes the outer model for adding edges between existing nodes
There is no necessity for an outer model for internal edges to be present. A line containing S means the graph produced will be “simple” (no repeated edges between the same node pair). A line beginning N describes part of the inner model for choosing nodes to connect to a new node. The line has the form shown below. Several lines beginning with N can make up the inner model for nodes to connect to new nodes. At least one such line must be present and the probabilities must total 1.
Similarly a line beginning with E specifies the inner model for choosing edges between existing nodes. This must be present if and only if the outer model for such edges (a line beginning ’e’) is present. Other than the change of letter it has the same form as above.
## Inner model componentsNode model components select what new nodes connect to lines have the form Model 1 – equal probabilities (random) Model 2 – proportional to node degree (d) Model 3 – proportional to d^(1 + delta log10 d) – PFP, delta parameter must be specified Model 4 – nodes have equal prob if node is a singleton (degree 1) zero otherwise Model 5 – nodes have equal prob if node is a doubleton (degree 2) zero otherwise Model 6 – prob is proportional to triangle count Model 7 – prob is const if node has been selected in last N steps (N is parameter)
For model 4,5,6 if there are no nodes which are singleton/doubleton/have triangles then all nodes have equal probability. Contact: Richard G. Clegg (richard@richardclegg.org) |