• SJSU Singular Matrix Database
  • Matrix group: HB
  • Click here for a description of the HB group.
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  • Matrix: HB/eris1176
  • Description: SYMMETRIC PATTERN OF ERISMAN, SUMMER 1973
  • download as a MATLAB mat-file, file size: 17 KB. Use SJget(116) or SJget('HB/eris1176') in MATLAB.
  • download in Matrix Market format, file size: 24 KB.
  • download in Rutherford/Boeing format, file size: 10 KB.

    HB/eris1176

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

    HB/eris1176

    dmperm of HB/eris1176

    Matrix properties (click for a legend)  
    number of rows1,176
    number of columns1,176
    structural full rank?yes
    structural rank1,176
    numerical rank 774
    dimension of the numerical null space402
    numerical rank / min(size(A))0.65816
    Euclidean norm of A 80.074
    calculated singular value # 7740.050045
    numerical rank defined using a tolerance
    max(size(A))*eps(norm(A)) =
    1.6712e-011
    calculated singular value # 7756.8194e-014
    gap in the singular values at the numerical rank:
    singular value # 774 / singular value # 775
    7.3386e+011
    calculated condition number1.3492e+068
    condestInf
    nonzeros18,552
    # of blocks from dmperm2
    # strongly connected comp.2
    entries not in dmperm blocks3
    explicit zero entries0
    nonzero pattern symmetrysymmetric
    numeric value symmetrysymmetric
    typebinary
    structuresymmetric
    Cholesky candidate?yes
    positive definite?no

    authorA. Erisman
    editorA. Curtis, I. Duff, J. Reid
    date1973
    kindpower network problem
    2D/3D problem?no
    SJid116
    UFid140

    Ordering statistics:AMD METIS DMPERM+
    nnz(chol(P*(A+A'+s*I)*P'))10,483 11,143 10,481
    Cholesky flop count3.2e+005 3.5e+005 3.2e+005
    nnz(L+U), no partial pivoting19,790 21,110 19,789
    nnz(V) for QR, upper bound nnz(L) for LU11,822 15,029 15,369
    nnz(R) for QR, upper bound nnz(U) for LU27,455 33,295 28,918

    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.