%-------------------------------------------------------------------------------
% SuiteSparse Matrix Collection, Tim Davis
% https://sparse.tamu.edu/SNAP/email-Eu-core
% name: SNAP/email-Eu-core
% [SNAP network: email-Eu-core network]
% id: 2784
% date: 2007
% author: J. Leskovec, J. Kleinberg and C. Faloutsos
% ed: J. Leskovec
% fields: name title A id date author ed kind notes aux
% aux: Communities_all
% kind: directed graph with communities
%-------------------------------------------------------------------------------
% notes:
% SNAP (Stanford Network Analysis Platform) Large Network Dataset Collection,
% Jure Leskovec and Anrej Krevl, http://snap.stanford.edu/data, June 2014.   
% email: jure at cs.stanford.edu                                             
%                                                                            
% email-Eu-core network                                                      
%                                                                            
% https://snap.stanford.edu/data/email-Eu-core.html                          
%                                                                            
% Dataset information                                                        
%                                                                            
% The network was generated using email data from a large European research  
% institution. We have anonymized information about all incoming and outgoing
% email between members of the research institution. There is an edge (u, v) 
% in the network if person u sent person v at least one email. The e-mails   
% only represent communication between institution members (the core), and   
% the dataset does not contain incoming messages from or outgoing messages to
% the rest of the world.                                                     
%                                                                            
% The dataset also contains "ground-truth" community memberships of the      
% nodes.  Each individual belongs to exactly one of 42 departments at the    
% research institute.                                                        
%                                                                            
% This network represents the "core" of the email-EuAll                      
% (https://snap.stanford.edu/data/email-EuAll.html) network, which also      
% contains links between members of the institution and people outside of the
% institution (although the node IDs are not the same).                      
%                                                                            
% Dataset statistics                                                         
% Nodes   1,005                                                              
% Edges   25,571                                                             
% Nodes in largest WCC    986 (0.981)                                        
% Edges in largest WCC    25552 (0.999)                                      
% Nodes in largest SCC    803 (0.799)                                        
% Edges in largest SCC    24729 (0.967)                                      
% Average clustering coefficient  0.3994                                     
% Number of triangles 105461                                                 
% Fraction of closed triangles    0.1085                                     
% Diameter (longest shortest path)    7                                      
% 90-percentile effective diameter    2.9                                    
%                                                                            
% Source (citation)                                                          
% Hao Yin, Austin R. Benson, Jure Leskovec, and David F. Gleich. "Local      
% Higher-order Graph Clustering." In Proceedings of the 23rd ACM SIGKDD      
% International Conference on Knowledge Discovery and Data Mining. 2017.     
%                                                                            
% J. Leskovec, J. Kleinberg and C. Faloutsos. Graph Evolution: Densification 
% and Shrinking Diameters. ACM Transactions on Knowledge Discovery from Data 
% (ACM TKDD), 1(1), 2007.                                                    
% http://www.cs.cmu.edu/~jure/pubs/powergrowth-tkdd.pdf                      
%                                                                            
% File    Description                                                        
% email-Eu-core.txt.gz                                                       
%     Email communication links between members of the institution           
% email-Eu-core-department-labels.txt.gz  Department membership labels       
%                                                                            
% Data format for community membership                                       
%                                                                            
%     NODEID DEPARTMENT                                                      
%     NODEID: id of the node (a member of the institute)                     
%     DEPARTMENT: id of the member's department (number in 0, 1, ..., 41)    
%                                                                            
% ---------------------------------------------------------------------------
% Notes on inclusion into the SuiteSparse Matrix Collection, July 2018:      
% ---------------------------------------------------------------------------
%                                                                            
% The SNAP grqph is 0-based with nodes numbered 0 to 1004.                   
%                                                                            
% In the SuiteSparse Matrix Collection, Problem.A is the directed graph,     
% where A(i,j)=1 if person 1+i sent person 1+j at least one email.           
% (1+, since the SNAP graph is 0-based).                                     
%                                                                            
% Each person is in exactly one community, so this could be represented      
% as a vector of size n, as node meta data.  However, to be consistent       
% with the other SNAP/com-* problems in the SuiteSparse Matrix               
% Collection, the community structure is represented as a sparse matrix,     
% created from the file email-Eu-core-department-labels.txt.                 
%                                                                            
% C = Problem.aux.Communities_all is a sparse matrix of size n by 42.        
% C(i,k)=1 if person 1+i is in department 1+k (again, 1+ to convert          
% the data to 1-based).  Thus, column C(:,k) represents the (1+k)th          
% community, where each community is a member's department.                  
%-------------------------------------------------------------------------------
