• 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/GD97_c
  • Description: Pajek network: Graph Drawing contest 1997
  • download as a MATLAB mat-file, file size: 11 KB. Use SJget(28) or SJget('Pajek/GD97_c') in MATLAB.
  • download in Matrix Market format, file size: 6 KB.
  • download in Rutherford/Boeing format, file size: 6 KB.


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


    scc of Pajek/GD97_c

    Pajek/GD97_c graph

    Matrix properties (click for a legend)  
    number of rows452
    number of columns452
    structural full rank?no
    structural rank63
    numerical rank 63
    dimension of the numerical null space389
    numerical rank / min(size(A))0.13938
    Euclidean norm of A 28.88
    calculated singular value # 630.53677
    numerical rank defined using a tolerance
    max(size(A))*eps(norm(A)) =
    calculated singular value # 643.0983e-014
    gap in the singular values at the numerical rank:
    singular value # 63 / singular value # 64
    calculated condition numberInf
    # of blocks from dmperm34
    # strongly connected comp.452
    explicit zero entries0
    nonzero pattern symmetry 0%
    numeric value symmetry 0%
    Cholesky candidate?no
    positive definite?no

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

    Additional fieldssize and type
    coordfull 452-by-3


    Pajek network converted to sparse adjacency matrix for inclusion in UF sparse 
    matrix collection, Tim Davis.  For Pajek datasets, See V. Batagelj & A. Mrvar,

    Ordering statistics:AMD METIS
    nnz(chol(P*(A+A'+s*I)*P'))920 941
    Cholesky flop count1.9e+003 2.0e+003
    nnz(L+U), no partial pivoting1,388 1,430
    nnz(V) for QR, upper bound nnz(L) for LU453 454
    nnz(R) for QR, upper bound nnz(U) for LU8,488 8,490

    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.