Edge metrics and functions

Edges can be accessed by storing the object returned from a call to add_edge(), by directly asking for a specific edge via edge(), or by iterating over all edges with in_edges, out_edges, or edges.

Edge structure and update history

By default an edge object in Raphtory will contain all updates over all layers between the given source and destination nodes. As an example, we can look at the two edges between FELIPE and MAKO (one for each direction).

In the code below we create the two edge objects by requesting them from the graph and then print out the layers each is involved in with layer_names. We can see that there are multiple behaviors in each direction represented within the edges.

Following this we access the history to get the earliest_time and latest_time. This update history consists all interactions across all layers.

Edge state functions

Edges have several functions for checking their state:

• is_active(): whether the edge is currently active (has updates in the current view)
• is_valid(): whether the edge exists and is valid in the current view
• is_deleted(): whether the edge has been deleted (at the time of the end of the view)
• is_self_loop(): whether the edge connects a node to itself

In an Event Graph, any edge that is present will be active, valid, and not deleted — unless you apply a view that removes all its history. These functions become more interesting with Persistent Graphs where edges can be explicitly deleted, which we discuss in the Time Semantics section.

Exploded edges

Raphtory offers you three different ways to split an edge by layer, depending on your use case:

• layers(): takes a list of layer names and returns a new Edge View which contains updates for only the specified layers. This is discussed in more detail in the Layer views chapter
• explode_layers(): returns an iterable of Edge Views, each containing the updates for one layer
• explode(): returns an Exploded Edge containing only the information from one call to add_edge(), in this case an edge object for each update.

In the code below you can see an example of each of these functions. We first call explode_layers(), to see which layer each edge object represents and output its update history. Next we fully explode() the edge and see each update as an individual object. Thirdly we use the layers() function to look at only the Touching and Carrying layers and chain this with a call to explode() to see the separate updates.