Matrix: DIMACS10/kron_g500-logn18

Description: DIMACS10 set: kronecker/kron_g500-logn18

DIMACS10/kron_g500-logn18 graph
(undirected graph drawing)


DIMACS10/kron_g500-logn18
scc of DIMACS10/kron_g500-logn18

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  • download as a MATLAB mat-file, file size: 53 MB. Use UFget(2491) or UFget('DIMACS10/kron_g500-logn18') in MATLAB.
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    Matrix properties
    number of rows262,144
    number of columns262,144
    nonzeros21,165,908
    # strongly connected comp.51,997
    explicit zero entries0
    nonzero pattern symmetrysymmetric
    numeric value symmetrysymmetric
    typeinteger
    structuresymmetric
    Cholesky candidate?no
    positive definite?no

    authorD. Bader, J. Berry, S. Kahan, R. Murphy, E. Reidy, J. Willcock
    editorD. Bader, J. Berry, S. Kahan, R. Murphy, E. Reidy, J. Willcock
    date2010
    kindundirected multigraph
    2D/3D problem?no

    Notes:

    10th DIMACS Implementation Challenge:                                   
                                                                            
    http://www.cc.gatech.edu/dimacs10/index.shtml                           
                                                                            
    As stated on their main website (                                       
    http://dimacs.rutgers.edu/Challenges/ ), the "DIMACS Implementation     
    Challenges address questions of determining realistic algorithm         
    performance where worst case analysis is overly pessimistic and         
    probabilistic models are too unrealistic: experimentation can provide   
    guides to realistic algorithm performance where analysis fails."        
                                                                            
    For the 10th DIMACS Implementation Challenge, the two related           
    problems of graph partitioning and graph clustering were chosen.        
    Graph partitioning and graph clustering are among the aforementioned    
    questions or problem areas where theoretical and practical results      
    deviate significantly from each other, so that experimental outcomes    
    are of particular interest.                                             
                                                                            
    Problem Motivation                                                      
                                                                            
    Graph partitioning and graph clustering are ubiquitous subtasks in      
    many application areas. Generally speaking, both techniques aim at      
    the identification of vertex subsets with many internal and few         
    external edges. To name only a few, problems addressed by graph         
    partitioning and graph clustering algorithms are:                       
                                                                            
        * What are the communities within an (online) social network?       
        * How do I speed up a numerical simulation by mapping it            
            efficiently onto a parallel computer?                           
        * How must components be organized on a computer chip such that     
            they can communicate efficiently with each other?               
        * What are the segments of a digital image?                         
        * Which functions are certain genes (most likely) responsible       
            for?                                                            
                                                                            
    Challenge Goals                                                         
                                                                            
        * One goal of this Challenge is to create a reproducible picture    
            of the state-of-the-art in the area of graph partitioning       
            (GP) and graph clustering (GC) algorithms. To this end we       
            are identifying a standard set of benchmark instances and       
            generators.                                                     
                                                                            
        * Moreover, after initiating a discussion with the community, we    
            would like to establish the most appropriate problem            
            formulations and objective functions for a variety of           
            applications.                                                   
                                                                            
        * Another goal is to enable current researchers to compare their    
            codes with each other, in hopes of identifying the most         
            effective algorithmic innovations that have been proposed.      
                                                                            
        * The final goal is to publish proceedings containing results       
            presented at the Challenge workshop, and a book containing      
            the best of the proceedings papers.                             
                                                                            
    Problems Addressed                                                      
                                                                            
    The precise problem formulations need to be established in the course   
    of the Challenge. The descriptions below serve as a starting point.     
                                                                            
        * Graph partitioning:                                               
                                                                            
          The most common formulation of the graph partitioning problem     
          for an undirected graph G = (V,E) asks for a division of V into   
          k pairwise disjoint subsets (partitions) such that all            
          partitions are of approximately equal size and the edge-cut,      
          i.e., the total number of edges having their incident nodes in    
          different subdomains, is minimized. The problem is known to be    
          NP-hard.                                                          
                                                                            
        * Graph clustering:                                                 
                                                                            
          Clustering is an important tool for investigating the             
          structural properties of data. Generally speaking, clustering     
          refers to the grouping of objects such that objects in the same   
          cluster are more similar to each other than to objects of         
          different clusters. The similarity measure depends on the         
          underlying application. Clustering graphs usually refers to the   
          identification of vertex subsets (clusters) that have             
          significantly more internal edges (to vertices of the same        
          cluster) than external ones (to vertices of another cluster).     
                                                                            
    There are 10 data sets in the DIMACS10 collection:                      
                                                                            
    Kronecker:  synthetic graphs from the Graph500 benchmark                
    dyn-frames: frames from a 2D dynamic simulation                         
    Delaunay:   Delaunay triangulations of random points in the plane       
    coauthor:   citation and co-author networks                             
    streets:    real-world street networks                                  
    Walshaw:    Chris Walshaw's graph partitioning archive                  
    matrix:     graphs from the UF collection (not added here)              
    random:     random geometric graphs (random points in the unit square)  
    clustering: real-world graphs commonly used as benchmarks               
    numerical:  graphs from numerical simulation                            
                                                                            
    Some of the graphs already exist in the UF Collection.  In some cases,  
    the original graph is unsymmetric, with values, whereas the DIMACS      
    graph is the symmetrized pattern of A+A'.  Rather than add duplicate    
    patterns to the UF Collection, a MATLAB script is provided at           
    http://www.cise.ufl.edu/research/sparse/dimacs10 which downloads        
    each matrix from the UF Collection via UFget, and then performs whatever
    operation is required to convert the matrix to the DIMACS graph problem.
    Also posted at that page is a MATLAB code (metis_graph) for reading the 
    DIMACS *.graph files into MATLAB.                                       
                                                                            
                                                                            
    Kronecker:  Kronecker Generator Graphs                                  
                                                                            
    The original Kronecker files contain self-loops and multiple edges.     
    These properties are also present in real-world data sets. However,     
    some tools cannot handle these "artifacts" at the moment. That is why   
    we present "cleansed" versions of the data sets as well.  For the       
    Challenge you should expect to be confronted with the original data     
    with self-loops and multiple edges. However, the final decision on      
    this issue will be made based on participant feedback.                  
                                                                            
    All files have been generated with the R-MAT parameters A=0.57, B=0.19, 
    C=0.19, and D=1-(A+B+C)=0.05 and edgefactor=48, i.e., the number of     
    edges equals 48*n, where n is the number of vertices. Details about the 
    generator and the parameter meanings can be found on the Graph500       
    website.  ( http://www.graph500.org/Specifications.html )               
                                                                            
    There are 12 graphs in the DIMACS10 test set at                         
    http://www.cc.gatech.edu/dimacs10/index.shtml .  Them come in 6 pairs.  
    One graph in each pair is a multigraph, with self-edges.  The other     
    graph is the nonzero pattern of the first (binary), with self-edges     
    removed.  MATLAB cannot directly represent multigraph, so in the UF     
    Collection the unweighted multigraph G is represented as a matrix A     
    where A(i,j) is an integer equal to the number edges (i,j) in G.        
                                                                            
    The binary graphs include the word 'simple' in their                    
    name In the UF Collection, only the multigraph is included,             
    since the simple graph can be constructed from the multigraph.          
    If A is the multigraph, the simple graph S can be computed as:          
                                                                            
       S = spones (tril (A,-1)) + spones (triu (A,1)) ;                     
                                                                            
    DIMACS10 graph:                        UF matrix:                       
    ---------------                        -------------                    
    kronecker/kron_g500-logn16             DIMACS10/kron_g500-logn16        
    kronecker/kron_g500-simple-logn16                                       
                                                                            
    kronecker/kron_g500-logn17             DIMACS10/kron_g500-logn17        
    kronecker/kron_g500-simple-logn17                                       
                                                                            
    kronecker/kron_g500-logn18             DIMACS10/kron_g500-logn18        
    kronecker/kron_g500-simple-logn18                                       
                                                                            
    kronecker/kron_g500-logn19             DIMACS10/kron_g500-logn19        
    kronecker/kron_g500-simple-logn19                                       
                                                                            
    kronecker/kron_g500-logn20             DIMACS10/kron_g500-logn20        
    kronecker/kron_g500-simple-logn20                                       
                                                                            
    kronecker/kron_g500-logn21             DIMACS10/kron_g500-logn21        
    kronecker/kron_g500-simple-logn21                                       
                                                                            
                                                                            
    References: "Introducing the Graph 500," Richard C. Murphy, Kyle B.     
    Wheeler, Brian W. Barrett, James A. Ang, Cray User's Group (CUG), May   
    5, 2010.                                                                
                                                                            
    D.A. Bader, J. Feo, J. Gilbert, J. Kepner, D. Koester, E. Loh, K.       
    Madduri, W. Mann, Theresa Meuse, HPCS Scalable Synthetic Compact        
    Applications #2 Graph Analysis (SSCA#2 v2.2 Specification), 5           
    September 2007.                                                         
                                                                            
    D. Chakrabarti, Y. Zhan, and C. Faloutsos, R-MAT: A recursive model     
    for graph mining, SIAM Data Mining 2004.                                
                                                                            
    Section 17.6, Algorithms in C (third edition). Part 5 Graph             
    Algorithms, Robert Sedgewick (Programs 17.7 and 17.8)                   
                                                                            
    P. Sanders, Random Permutations on Distributed, External and            
    Hierarchical Memory, Information Processing Letters 67 (1988) pp        
    305-309.                                                                
                                                                            
    "DFS: A Simple to Write Yet Difficult to Execute Benchmark," Richard C. 
    Murphy, Jonathan Berry, William McLendon, Bruce Hendrickson, Douglas    
    Gregor, Andrew Lumsdaine, IEEE International Symposium on Workload      
    Characterizations 2006 (IISWC06), San Jose, CA, 25-27 October 2006.     
                                                                            
    ---- sample code for generating these matrices:                         
                                                                            
    function ij = kronecker_generator (SCALE, edgefactor)                   
    %% Generate an edgelist according to the Graph500                       
    %% parameters.  In this sample, the edge list is                        
    %% returned in an array with two rows, where StartVertex                
    %% is first row and EndVertex is the second.  The vertex                
    %% labels start at zero.                                                
    %%                                                                      
    %% Example, creating a sparse matrix for viewing:                       
    %%   ij = kronecker_generator (10, 16);                                 
    %%   G = sparse (ij(1,:)+1, ij(2,:)+1, ones (1, size (ij, 2)));         
    %%   spy (G);                                                           
    %% The spy plot should appear fairly dense. Any locality                
    %% is removed by the final permutations.                                
                                                                            
      %% Set number of vertices.                                            
      N = 2^SCALE;                                                          
                                                                            
      %% Set number of edges.                                               
      M = edgefactor * N;                                                   
                                                                            
      %% Set initiator probabilities.                                       
      [A, B, C] = deal (0.57, 0.19, 0.19);                                  
                                                                            
      %% Create index arrays.                                               
      ij = ones (2, M);                                                     
      %% Loop over each order of bit.                                       
      ab = A + B;                                                           
      c_norm = C/(1 - (A + B));                                             
      a_norm = A/(A + B);                                                   
                                                                            
      for ib = 1:SCALE,                                                     
        %% Compare with probabilities and set bits of indices.              
        ii_bit = rand (1, M) > ab;                                          
        jj_bit = rand (1, M) > ( c_norm * ii_bit + a_norm * not (ii_bit) ); 
        ij = ij + 2^(ib-1) * [ii_bit; jj_bit];                              
      end                                                                   
                                                                            
      %% Permute vertex labels                                              
      p = randperm (N);                                                     
      ij = p(ij);                                                           
                                                                            
      %% Permute the edge list                                              
      p = randperm (M);                                                     
      ij = ij(:, p);                                                        
                                                                            
      %% Adjust to zero-based labels.                                       
      ij = ij - 1;                                                          
                                                                            
    function G = kernel_1 (ij)                                              
    %% Compute a sparse adjacency matrix representation                     
    %% of the graph with edges from ij.                                     
                                                                            
      %% Remove self-edges.                                                 
      ij(:, ij(1,:) == ij(2,:)) = [];                                       
      %% Adjust away from zero labels.                                      
      ij = ij + 1;                                                          
      %% Find the maximum label for sizing.                                 
      N = max (max (ij));                                                   
      %% Create the matrix, ensuring it is square.                          
      G = sparse (ij(1,:), ij(2,:), ones (1, size (ij, 2)), N, N);          
      %% Symmetrize to model an undirected graph.                           
      G = spones (G + G.');                                                 
    

    For a description of the statistics displayed above, click here.

    Maintained by Tim Davis, last updated 12-Mar-2014.
    Matrix pictures by cspy, a MATLAB function in the CSparse package.
    Matrix graphs by Yifan Hu, AT&T Labs Visualization Group.