• 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/n3c4-b2
  • Description: Simplicial complexes from Homology from Volkmar Welker.
  • download as a MATLAB mat-file, file size: 1 KB. Use SJget(546) or SJget('JGD_Homology/n3c4-b2') in MATLAB.
  • download in Matrix Market format, file size: 740 bytes.
  • download in Rutherford/Boeing format, file size: 772 bytes.

    JGD_Homology/n3c4-b2

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

    JGD_Homology/n3c4-b2

    Matrix properties (click for a legend)  
    number of rows20
    number of columns15
    structural full rank?yes
    structural rank15
    numerical rank 10
    dimension of the numerical null space5
    numerical rank / min(size(A))0.66667
    Euclidean norm of A 2.4495
    calculated singular value # 102.4495
    numerical rank defined using a tolerance
    max(size(A))*eps(norm(A)) =
    8.8818e-015
    calculated singular value # 114.4339e-016
    gap in the singular values at the numerical rank:
    singular value # 10 / singular value # 11
    5.5245e+015
    calculated condition number2.1193e+016
    condest-2
    nonzeros60
    # 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
    SJid546
    UFid2,086

    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/n3c4.b2.20x15.sms      
    

    Ordering statistics:AMD METIS
    nnz(V) for QR, upper bound nnz(L) for LU123 125
    nnz(R) for QR, upper bound nnz(U) for LU105 105

    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.