Louvain

Function

This API is used to run the Louvain algorithm based on input parameters.

Louvain is a modularity-based community detection algorithm with high efficiency and effect. It detects hierarchical community structures and aims to maximize the modularity of the entire community network.

URI

POST /ges/v1.0/{project_id}/hyg/{graph_name}/algorithm

**Table 1** URI parameters
Parameter	Mandatory	Type	Description
project_id	Yes	String	Project ID. For how to obtain the project ID, see Obtaining a Project ID.
graph_name	Yes	String	Graph name

Request Parameters

**Table 2** Request body parameters
Parameter	Mandatory	Type	Description
algorithmName	Yes	String	Algorithm name
parameters	Yes	parameters Object	Algorithm parameters

**Table 3** parameters
Parameter	Mandatory	Type	Description
convergence	No	Double	Convergence accuracy. The value range is (0, 1). The default value is 0.00001.
max_iterations	No	Integer	Maximum iterations. An integer ranging from 1 to 2147483647. For frontend calls, the range is [1, 2000]. The default value is 100.
weight	No	String	Weight of an edge. The value can be empty or a string. If this property is not configured for the edge in a graph, the algorithm reports an error. Empty: The default weight and distance of edges are 1. String: The property of the corresponding edge is used as the weight.

Either OD_pairs or seeds must be specified. If they are both specified, the OD_pair value prevails.

Response Parameters

Parameter	Type	Description
errorMessage	String	System prompt. If execution succeeds, this parameter may be left blank. If the execution fails, this parameter is used to display the error message.
errorCode	String	System prompt. If execution succeeds, this parameter may be left blank. If the execution fails, this parameter is used to display the error code.
jobId	String	ID of the algorithm execution job. This parameter is left blank when the request fails. NOTE: You can use the returned job ID to view the task execution status and obtain the algorithm return result. For details, see Querying Job Status on the Service Plane (1.0.0).
jobType	Integer	Job type. This parameter is left blank when the request fails.

Example Request

POST http://{SERVER_URL}/ges/v1.0/{project_id}/hyg/{graph_name}/algorithm  
{ 
 "algorithmName":"louvain", 
 "parameters":{ 
        "convergence":0.00001, 
        "max_iterations":100
 } 
}

SERVER_URL: Address for accessing a graph. For details about its value, see Using Service Plane APIs.

Example Response

Status code: 200

Example response for a successful request

Http Status Code: 200
{  
"jobId": "4448c9fb-0b16-4a78-8d89-2a137c53454a001679122",
"jobType": 1
}

Status code: 400

Example response for a failed request

Http Status Code: 400
{
"errorMessage":"graph [demo] is not found",
"errorCode":"GES.8402"
}

Status Codes

Return Value	Description
400 Bad Request	Request error.
401 Unauthorized	Authorization failed.
403 Forbidden	No operation permissions.
404 Not Found	No resources found.
500 Internal Server Error	Internal server error.
503 Service Unavailable	Service unavailable.