• SJSU Singular Matrix Database
  • Matrix group: JGD_Homology
  • Click here for a description of the JGD_Homology group.
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  • Matrix: JGD_Homology/n4c5-b2
  • Description: Simplicial complexes from Homology from Volkmar Welker.
  • download as a MATLAB mat-file, file size: 4 KB. Use SJget(581) or SJget('JGD_Homology/n4c5-b2') in MATLAB.
  • download in Matrix Market format, file size: 4 KB.
  • download in Rutherford/Boeing format, file size: 4 KB.

    JGD_Homology/n4c5-b2

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

    JGD_Homology/n4c5-b2

    Matrix properties (click for a legend)  
    number of rows455
    number of columns105
    structural full rank?yes
    structural rank105
    numerical rank 91
    dimension of the numerical null space14
    numerical rank / min(size(A))0.86667
    Euclidean norm of A 3.873
    calculated singular value # 913.873
    numerical rank defined using a tolerance
    max(size(A))*eps(norm(A)) =
    2.0206e-013
    calculated singular value # 923.5573e-015
    gap in the singular values at the numerical rank:
    singular value # 91 / singular value # 92
    1.0887e+015
    calculated condition number4.65e+015
    condest-2
    nonzeros1,365
    # of blocks from dmperm1
    # strongly connected comp.1
    entries not in dmperm blocks0
    explicit zero entries0
    nonzero pattern symmetry 0%
    numeric value symmetry 0%
    typeinteger
    structurerectangular
    Cholesky candidate?no
    positive definite?no

    authorV. Welker
    editorJ.-G. Dumas
    date2008
    kindcombinatorial problem
    2D/3D problem?no
    SJid581
    UFid2,110

    Notes:

    Simplicial complexes from Homology from Volkmar Welker.     
    From Jean-Guillaume Dumas' Sparse Integer Matrix Collection,
    http://ljk.imag.fr/membres/Jean-Guillaume.Dumas/simc.html   
                                                                
    http://www.mathematik.uni-marburg.de/~welker/               
                                                                
    Filename in JGD collection: Homology/n4c5.b2.455x105.sms    
    

    Ordering statistics:AMD METIS
    nnz(V) for QR, upper bound nnz(L) for LU28,079 27,136
    nnz(R) for QR, upper bound nnz(U) for LU4,200 4,200

    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.