Matrix: HB/eris1176

Description: SYMMETRIC PATTERN OF ERISMAN, SUMMER 1973

HB/eris1176 graph
(undirected graph drawing)


HB/eris1176 dmperm of HB/eris1176

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  • Matrix group: HB
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  • download as a MATLAB mat-file, file size: 9 KB. Use UFget(140) or UFget('HB/eris1176') in MATLAB.
  • download in Matrix Market format, file size: 23 KB.
  • download in Rutherford/Boeing format, file size: 9 KB.

    Matrix properties
    number of rows1,176
    number of columns1,176
    nonzeros18,552
    structural full rank?yes
    structural rank1,176
    # of blocks from dmperm2
    # strongly connected comp.2
    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

    Ordering statistics:result
    nnz(chol(P*(A+A'+s*I)*P')) with AMD10,483
    Cholesky flop count3.2e+05
    nnz(L+U), no partial pivoting, with AMD19,790
    nnz(V) for QR, upper bound nnz(L) for LU, with COLAMD11,822
    nnz(R) for QR, upper bound nnz(U) for LU, with COLAMD27,455

    SVD-based statistics:
    norm(A)80.0739
    min(svd(A))0
    cond(A)Inf
    rank(A)774
    sprank(A)-rank(A)402
    null space dimension402
    full numerical rank?no
    singular value gap1.43856e+12

    singular values (MAT file):click here
    SVD method used:s = svd (full (A)) ;
    status:ok

    HB/eris1176 svd

    For a description of the statistics displayed above, click here.

    Maintained by Tim Davis, last updated 12-Mar-2014.
    Matrix pictures by cspy, a MATLAB function in the CSparse package.
    Matrix graphs by Yifan Hu, AT&T Labs Visualization Group.