Induced Subgraph

Overview

The Induced Subgraph algorithm is used to compute the induced subgraph of a given set of nodes in a graph. It provides a way to focus on the immediate connections and gain insights into the local structure and interactions within the selected subset of nodes.

Concepts

Induced Subgraph

An induced subgraph includes only the nodes from the given set and the edges that connect those nodes.

As this example shows, when specifying node set S = {A, B, I, K, L, M, N}, the induced subgraph is the graph whose node set is S and whose edge set contains all edges that have both endpoints in S.

Ultipa's Induced Subgraph algorithm returns all the 1-step paths in the induced subgraph.

Considerations

• The Induced Subgraph algorithm ignores the direction of edges but calculates them as undirected edges.

Syntax

• Command: algo(subgraph)
• Parameters:

Examples

The example graph is as follows:

File Writeback

UQL
algo(subgraph).params({
  ids: ['A','C','D','G']
}).write({
  file:{
    filename: 'paths'
    }
})

Results: File paths

File
C--[102]--A
C--[105]--D
D--[107]--A
D--[106]--A
G--[109]--G

Direct Return

UQL
algo(subgraph).params({
  ids: ['A','C','D','G']
}) as subgraph
return subgraph

Results: subgraph

Stream Return

UQL
algo(subgraph).params({
  uuids: [6,7]
}).stream() as p
with pedges(p) as e
find().edges(e) as edges
return max(edges.score)

Results: 5