Find Shortest Path Between People in Social Neighborhood

Connect to Neo4j Database

Create a Neo4j connection object neo4jconn using the URL http://localhost:7474/db/data, user name neo4j, and password matlab.

url = 'http://localhost:7474/db/data';
username = 'neo4j';
password = 'matlab';

neo4jconn = neo4j(url,username,password);

Check the Message property of the Neo4j connection object neo4jconn. The blank Message property indicates a successful connection.

neo4jconn.Message

ans =

     []

Search Entire Graph

Find all the Person nodes and all the relationships associated with each Person node using searchGraph.

social_graphdata = searchGraph(neo4jconn,{'Person'})

social_graphdata = struct with fields:
        Nodes: [7×3 table]
    Relations: [8×5 table]

Convert Graph Data to Directed Graph

Using the table social_graphdata.Nodes, access the name property for each node that appears in the NodeData variable of the table.

Assign the table social_graphdata.Nodes to nodestable.

nodestable = social_graphdata.Nodes

nodestable=7×3 table
         NodeLabels      NodeData                  NodeObject             
         __________    ____________    ___________________________________

    0     'Person'     [1×1 struct]    [1x1 database.neo4j.http.Neo4jNode]
    1     'Person'     [1×1 struct]    [1x1 database.neo4j.http.Neo4jNode]
    2     'Person'     [1×1 struct]    [1x1 database.neo4j.http.Neo4jNode]
    3     'Person'     [1×1 struct]    [1x1 database.neo4j.http.Neo4jNode]
    4     'Person'     [1×1 struct]    [1x1 database.neo4j.http.Neo4jNode]
    5     'Person'     [1×1 struct]    [1x1 database.neo4j.http.Neo4jNode]
    9     'Person'     [1×1 struct]    [1x1 database.neo4j.http.Neo4jNode]

Assign the row names for each row in the table nodestable to rownames.

rownames = nodestable.Properties.RowNames

rownames = 7×1 cell array
    {'0'}
    {'1'}
    {'2'}
    {'3'}
    {'4'}
    {'5'}
    {'9'}

Access the NodeData variable from nodestable for each row. nodedata contains an array of structures.

nodedata = [nodestable.NodeData{rownames}]

nodedata = 1×7 struct array with fields:
    name

To retrieve the name field from each structure, index into the array. nodenames is a cell array of character vectors that contains node names.

nodenames = {nodedata(:).name}

nodenames = 1×7 cell array
    {'User1'}    {'User3'}    {'User2'}    {'User4'}    {'User5'}    {'User6'}    {'User7'}

Create the digraph object social_graph using the neo4jStruct2Digraph function with the graph data stored in social_graphdata and the node names stored in nodenames.

social_graph = neo4jStruct2Digraph(social_graphdata,'NodeNames',nodenames)

social_graph = 
  digraph with properties:

    Edges: [8×3 table]
    Nodes: [7×3 table]

To see a visual representation of the graph, create a figure that displays social_graph.

plot(social_graph,'EdgeLabel',social_graph.Edges.RelationType)

Find Shortest Path

Find the shortest path between User1 and User7 using shortestpath.

[user1_to_user7,distance] = shortestpath(social_graph,'User1','User7')

user1_to_user7 = 1×5 cell array
    {'User1'}    {'User3'}    {'User4'}    {'User6'}    {'User7'}

distance = 4

Close Database Connection

close(neo4jconn)