• SJSU Singular Matrix Database
  • Matrix group: Pajek
  • Click here for a description of the Pajek group.
  • Click here for a list of all matrices
  • Click here for a list of all matrix groups

  • Matrix: Pajek/GD00_c
  • Description: Pajek network: Graph Drawing contest 2000
  • download as a MATLAB mat-file, file size: 22 KB. Use SJget(12) or SJget('Pajek/GD00_c') in MATLAB.
  • download in Matrix Market format, file size: 11 KB.
  • download in Rutherford/Boeing format, file size: 11 KB.


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


    scc of Pajek/GD00_c

    Pajek/GD00_c graph

    Matrix properties (click for a legend)  
    number of rows638
    number of columns638
    structural full rank?no
    structural rank302
    numerical rank 300
    dimension of the numerical null space338
    numerical rank / min(size(A))0.47022
    Euclidean norm of A 9.3891
    calculated singular value # 3000.19009
    numerical rank defined using a tolerance
    max(size(A))*eps(norm(A)) =
    calculated singular value # 3013.9349e-015
    gap in the singular values at the numerical rank:
    singular value # 300 / singular value # 301
    calculated condition numberInf
    # of blocks from dmperm138
    # strongly connected comp.566
    explicit zero entries0
    nonzero pattern symmetry 2%
    numeric value symmetry 2%
    Cholesky candidate?no
    positive definite?no

    authorGraph Drawing Contest
    editorV. Batagelj
    kinddirected multigraph
    2D/3D problem?no

    Additional fieldssize and type
    nodenamefull 638-by-76
    coordfull 638-by-2


    Pajek network converted to sparse adjacency matrix for inclusion in UF sparse 
    matrix collection, Tim Davis.  For Pajek datasets, See V. Batagelj & A. Mrvar,
    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'))2,286 2,620
    Cholesky flop count1.4e+004 2.3e+004
    nnz(L+U), no partial pivoting3,934 4,602
    nnz(V) for QR, upper bound nnz(L) for LU6,666 5,267
    nnz(R) for QR, upper bound nnz(U) for LU6,031 6,515

    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.