Source Code of Community Detection in Dynamic Networks - IncNSA

The implementation of IncNSA: "IncNSA: Detecting communities incrementally from time-evolving networks based on node similarity".

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If you find this method helpful for your research, please cite this paper.

@article{su2020incnsa,  
      title={IncNSA: Detecting communities incrementally from time-evolving networks based on node similarity},  
      author={Su, Xing and Cheng, Jianjun and Yang, Haijuan and Leng, Mingwei and Zhang, Wenbo and Chen, Xiaoyun},  
      journal={International Journal of Modern Physics C},  
      volume={31},   
      number={07},  
      pages={2050094},  
      year={2020},  
      publisher={World Scientific}  
} 

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Requirement

The code of NSA has been tested running under Python 3.7.6, with the following packages installed (along with their dependencies):

• networkx == 2.4

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Data Format

• The input data of each timestamp is in .edgelist format, in which each line contains two integers: source node id and target node id of an undirected edge.
• The naming of the dynamic network datasets must begins at 1 and be continuous without suffix. For example, if a dynamic network contains 3 timestamps, their file names are 1, 2, 3, respectively.
• Synthetic dynamic networks are given as examples in ./syn_datasets (generation of the synthetic networks refers to the paper).

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How to Use

1. Initialization: run main1_initial.py to initialize the network at the 1st time step. Here we use NSA algorithm (from paper "Neighbor Similarity Based Agglomerative Method for Community Detection in Networks") for initialization, other methods also can be ulitized to obtain the communities at the 1st time step. Paramaters setting in main1_initial.py is as follows (take dataset birth_death as example):

    merge_ratio = 0.2  #The parameter of NSA, usually less than 0.3.  
    graph = nx.Graph(nx.read_edgelist("./syn_datasets/birth_death/birth_death_data/1")) # Path of input data at the 1st time step.  
    path = r'./syn_datasets/birth_death' # The file directory of a dataset that is the upper level directory of the input data, to save input data, groundtruth, evolving information, community results and evaluation results.   
   

2. Detecting Communities Incrementally: run main2.py to detecting communities in dynamic networks incrementally based on previous time step. Paramaters setting in main2.py is as follows (take dataset birth_death as example):

    n_stampt = 10 # The number of time steps. 
    path = r'./syn_datasets/birth_death' # The file directory of a dataset. 
    path_dataset = r'./syn_datasets/birth_death/birth_death_data' # The path of input data contains all time steps.  
    
    # The value of 'path' in main1_initial.py and main2.py must be the same, the value of 'path_dataset' which should keep the same upper level directory. 
   

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Output Files

1. After running main1_initial.py, the community result of time step 1 can be obtained (see ./syn_datasets/birth_death/community/community1.txt for example).

2. After running main2.py, the the community results of all the time steps can be obtained. The output files include (take dataset birth_death as example):

   • ./syn_datasets/birth_death/community: the results of communities.
   • ./syn_datasets/birth_death/pre_inform: evolution information of nodes and edges between the two consecutive time steps.
   • ./syn_datasets/birth_death/Q.txt: evaluation results by modularity.

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Disclaimer

If you find any bugs, please report them to me xing.su2@hdr.mq.edu.au.