Weakly Connected Components

Introduction

The Weakly Connected Components (WCC) algorithm identifies connected components within a directed graph, disregarding edge direction.

Output

The algorithm outputs the following fields:

Field Name	Description
id	The ID of the vertex (node)
componentId	A generated integer ID representing the component of the vertex

Using Cypher

Query Example

CALL algo.wcc({
    labels: ['User'],
    relationshipTypes: ['LINK'],
    seedProperty: 'name',
    threshold: 1.0,
    maxIterations: 30,
    minComponentSize: 5
    }) YIELD id, componentId
RETURN id, componentId

Parameters

Name	Description	Required
labels	Specifies the node labels to include in the algorithm	Yes
relationshipTypes	Specifies the relationship types to include	Yes
relationshipWeightProperty	Defines the property name for edge weights	No
seedProperty	The node property used as the seed for the component ID	No
threshold	Minimum edge weight value for it to be included in the algorithm	No
minComponentSize	Minimum size of the components to be returned	No

Exporting Query Results

For large datasets, export the results to object storage:

EXPORT TO 's3://my_bucket/target_dir'
PROPERTIES {
  catalog: 'puppygraph_catalog_name'
}
CALL algo.wcc({
    labels: ['User'],
    relationshipTypes: ['LINK'],
    relationshipWeightProperty: 'weight',
    threshold: 1.0
    }) YIELD id, componentId
RETURN id, componentId

Using Gremlin

Query Example

graph.compute().program(
  WeakConnectedComponentProgram.build()
    .maxIteration(20)
    .vertices("User")
    .edges("LINK")
    .edgeProperties("amount")
    .setParam("weight", "amount", "threshold", 10.0)
    .create()
).submit().get().toList()

Parameters

Method	Description
maxIteration(int n)	Sets the maximum iteration count, default is 30
vertices(String... names)	Specifies the vertex labels to include
edges(String... names)	Specifies the edge labels to include
edgeProperties(String... names)	Defines the property name for edge weights
setParams(Object... args)	Adds additional parameters using alternating keys and values

Additional Parameters

Key	Description	Default Value
weight	Specifies the edge weight property or a constant value as weight	1.0
threshold	Minimum edge weight value for it to be included in the algorithm	0.0
seedProperty	The vertex property used as the component ID seed	"id"
minComponentSize	Minimum size of the components to be returned	0

Exporting Query Results

For large datasets, use the save() method to export the results.

graph.compute().program(
    WeakConnectedComponentProgram.build()
            .maxIteration(20)
            .vertices("User")
            .edges("LINK")
            .edgeProperties("amount")
            .setParam("weight", "amount", "threshold", 10.0)
            .create()
).submit().get().save([
  "exportTo": "s3://my_bucket/target_dir",
  "catalog": "puppygraph_catalog_name"
])