Matrix: HB/jpwh_991

Description: UNSYMMETRIC MATRIX FROM PHILIPS LTD, J.P.WHELAN,1978.

HB/jpwh_991 graph HB/jpwh_991 graph
(bipartite graph drawing) (graph drawing of A+A')


HB/jpwh_991 dmperm of HB/jpwh_991

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  • Matrix group: HB
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  • download as a MATLAB mat-file, file size: 12 KB. Use UFget(187) or UFget('HB/jpwh_991') in MATLAB.
  • download in Matrix Market format, file size: 19 KB.
  • download in Rutherford/Boeing format, file size: 14 KB.

    Matrix properties
    number of rows991
    number of columns991
    nonzeros6,027
    structural full rank?yes
    structural rank991
    # of blocks from dmperm146
    # strongly connected comp.146
    explicit zero entries0
    nonzero pattern symmetry 94%
    numeric value symmetry 94%
    typeinteger
    structureunsymmetric
    Cholesky candidate?no
    positive definite?no

    authorJ. Whelan
    editorI. Duff, R. Grimes, J. Lewis
    date1978
    kindsemiconductor device problem
    2D/3D problem?yes

    Ordering statistics:result
    nnz(chol(P*(A+A'+s*I)*P')) with AMD28,358
    Cholesky flop count2.2e+06
    nnz(L+U), no partial pivoting, with AMD55,725
    nnz(V) for QR, upper bound nnz(L) for LU, with COLAMD65,321
    nnz(R) for QR, upper bound nnz(U) for LU, with COLAMD117,974

    SVD-based statistics:
    norm(A)16.292
    min(svd(A))0.114696
    cond(A)142.045
    rank(A)991
    sprank(A)-rank(A)0
    null space dimension0
    full numerical rank?yes

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

    HB/jpwh_991 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.