• SJSU Singular Matrix Database
  • Matrix group: Pajek
  • Click here for a description of the Pajek group.
  • Click here for a list of all matrices
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  • Matrix: Pajek/GD01_b
  • Description: Pajek network: Graph Drawing contest 2001
  • download as a MATLAB mat-file, file size: 2 KB. Use SJget(14) or SJget('Pajek/GD01_b') in MATLAB.
  • download in Matrix Market format, file size: 1 KB.
  • download in Rutherford/Boeing format, file size: 1 KB.

    Pajek/GD01_b

    Routine svd from Matlab 7.6.0.324 (R2008a) used to calculate the singular values.

    Pajek/GD01_b

    Pajek/GD01_b graph

    Matrix properties (click for a legend)  
    number of rows18
    number of columns18
    structural full rank?no
    structural rank17
    numerical rank 17
    dimension of the numerical null space1
    numerical rank / min(size(A))0.94444
    Euclidean norm of A 2.358
    calculated singular value # 170.14015
    numerical rank defined using a tolerance
    max(size(A))*eps(norm(A)) =
    7.9936e-015
    calculated singular value # 180
    gap in the singular values at the numerical rank:
    singular value # 17 / singular value # 18
    Inf
    calculated condition numberInf
    condestInf
    nonzeros37
    # of blocks from dmperm5
    # strongly connected comp.1
    explicit zero entries0
    nonzero pattern symmetry 51%
    numeric value symmetry 51%
    typebinary
    structureunsymmetric
    Cholesky candidate?no
    positive definite?no

    authorGraph Drawing Contest
    editorV. Batagelj
    date2001
    kinddirected graph
    2D/3D problem?no
    SJid14
    UFid1,479

    Additional fieldssize and type
    nodenamefull 18-by-22
    coordfull 18-by-2

    Notes:

    ------------------------------------------------------------------------------
    Pajek network converted to sparse adjacency matrix for inclusion in UF sparse 
    matrix collection, Tim Davis.  For Pajek datasets, See V. Batagelj & A. Mrvar,
    http://vlado.fmf.uni-lj.si/pub/networks/data/.                                
    ------------------------------------------------------------------------------
    The original problem had 3D xyz coordinates, but all values of z were equal   
    to 0.5, and have been removed.  This graph has 2D coordinates.                
    

    Ordering statistics:AMD METIS
    nnz(chol(P*(A+A'+s*I)*P'))50 54
    Cholesky flop count1.4e+002 1.7e+002
    nnz(L+U), no partial pivoting82 90
    nnz(V) for QR, upper bound nnz(L) for LU30 31
    nnz(R) for QR, upper bound nnz(U) for LU41 43

    Maintained by Leslie Foster, last updated 24-Apr-2009.

    Entries 5 through 14 in the table of matrix properties and the singular
    value plot were created using SJsingular code. The other plots
    and statistics are produced using utilities from the SuiteSparse package.
    Matrix color plot pictures by cspy, a MATLAB function in the CSparse package.