Matrix: HB/will199

Description: UNSYMMETRIC PATTERN OF ORDER 199 GIVEN BY WILLOUGHBY IN REID, 1970

HB/will199 graph HB/will199 graph
(bipartite graph drawing) (graph drawing of A+A')


HB/will199 dmperm of HB/will199

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  • Matrix group: HB
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  • download as a MATLAB mat-file, file size: 2 KB. Use UFget(273) or UFget('HB/will199') in MATLAB.
  • download in Matrix Market format, file size: 2 KB.
  • download in Rutherford/Boeing format, file size: 2 KB.

    Matrix properties
    number of rows199
    number of columns199
    nonzeros701
    structural full rank?yes
    structural rank199
    # of blocks from dmperm10
    # strongly connected comp.1
    explicit zero entries0
    nonzero pattern symmetry 6%
    numeric value symmetry 6%
    typebinary
    structureunsymmetric
    Cholesky candidate?no
    positive definite?no

    authorR. Willoughby
    editorI. Duff, R. Grimes, J. Lewis
    date1979
    kindstructural problem
    2D/3D problem?yes

    Ordering statistics:result
    nnz(chol(P*(A+A'+s*I)*P')) with AMD4,595
    Cholesky flop count1.9e+05
    nnz(L+U), no partial pivoting, with AMD8,991
    nnz(V) for QR, upper bound nnz(L) for LU, with COLAMD1,230
    nnz(R) for QR, upper bound nnz(U) for LU, with COLAMD2,403

    SVD-based statistics:
    norm(A)4.38808
    min(svd(A))7.39959e-18
    cond(A)5.93016e+17
    rank(A)191
    sprank(A)-rank(A)8
    null space dimension8
    full numerical rank?no
    singular value gap4.90955e+13

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

    HB/will199 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.