Matrix: Buss/connectus

Description: Website recommendation system, Steven Buss, Univ. Florida

Buss/connectus graph
(bipartite graph drawing)

scc of Buss/connectus

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  • download as a MATLAB mat-file, file size: 1 MB. Use UFget(2247) or UFget('Buss/connectus') in MATLAB.
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    Matrix properties
    number of rows512
    number of columns394,792
    structural full rank?no
    structural rank458
    # of blocks from dmperm8
    # strongly connected comp.256
    explicit zero entries0
    nonzero pattern symmetry 0%
    numeric value symmetry 0%
    Cholesky candidate?no
    positive definite?no

    authorS. Buss
    editorT. Davis
    kindundirected bipartite graph
    2D/3D problem?no


    This is a matrix from Steven Buss, for a website recommendation system (to
    be called  Each row of the matrix is a unique user. 
    Eachc olumn of the matrix is a web page.  A(i,j)=1 if user i has tagged   
    web page j as favorable, and a 0 represents no opinion.  The data was     
    obtained from  Note that the matrix A*A' contains one           
    connected component of size 342, and 170 singletons (nodes with no edges) 
    This means that a group of 341 users share some interests, at least       
    indirectly, and that there are 171 other users that share no interests    
    at all with any other users (they have no pages in common with anyone).   

    SVD-based statistics:
    null space dimension56
    full numerical rank?no
    singular value gap1.03249e+10

    singular values (MAT file):click here
    SVD method used:s = svd (full (R)) ; where [~,R,E] = spqr (A') with droptol of zero

    Buss/connectus svd

    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.