Metagraph Feature Format

First line is a single integer n representing the number of dimensions of the feature vectors, i.e., the number of anchored metagraphs.

The next n lines describe the anchored metagraphs, each line for one anchored metagraph. Each anchored metagraph is a feature, summarized by four integers separated by tab characters in the following form:

[FeatureID]<tab>[MetagraphID]<tab>[HeadColor]<tab>[TailColor],

where

• [FeatureID] is the ID of a feature, i.e., an anchored metagraph. Note that an anchored metagraph is defined by the triple (metagraph, head, node), as described by the next three integers;

• [MetagraphID] is the ID of the corresponding metagraph in the anchored metagraph;

• [HeadColor] is the color of the head anchor in the metagraph;

• [TailColor] is the color of the tail anchor in the metagraph.

The remaining lines contain the feature vectors. Each line represents a feature vector of one node or node pair in the following form:

[HeadID]<tab>[TailID]<tab>[FeatureID]:[FeatureValue]<tab>[FeatureID]:[FeatureValue]...,

where

• the first two fields [HeadID] / [TailID] is the ID of the head / tail node in a heterogeneous graph, i.e., this line is a feature vector for the node pair with head / tail roles in each metagraph. Either [HeadID] or [TaiIID] can be -1, in which case this is the feature vector of a single node with a head or tail role;

• subsequent fields contain the sparse representation of a feature vector in the form of one or more [FeatureID]:[FeatureValue] entries. In particular, [FeatureID] is the ID of a feature (i.e., an anchored metagraph), and [FeatureValue] is a float type indicating the value of the feature (e.g., number of instances of the anchored metagraph containing this node pair with matching roles).