Matrix: HB/gre_216b

Description: UNSYMMETRIC MATRIX FROM GRENOBLE,FRANCOIS CACHARD,MARCH 1981.

HB/gre_216b graph HB/gre_216b graph
(bipartite graph drawing) (graph drawing of A+A')

HB/gre_216b

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  • Matrix group: HB
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  • download as a MATLAB mat-file, file size: 3 KB. Use UFget(164) or UFget('HB/gre_216b') in MATLAB.
  • download in Matrix Market format, file size: 3 KB.
  • download in Rutherford/Boeing format, file size: 3 KB.

    Matrix properties
    number of rows216
    number of columns216
    nonzeros812
    # strongly connected comp.1
    explicit zero entries64
    nonzero pattern symmetry 0%
    numeric value symmetry 0%
    typereal
    structureunsymmetric
    Cholesky candidate?no
    positive definite?no

    authorF. Cachard
    editorI. Duff, R. Grimes, J. Lewis
    date1981
    kinddirected weighted graph
    2D/3D problem?no

    Note that all matrix statistics (except nonzero pattern symmetry) exclude the 64 explicit zero entries.

    SVD-based statistics:
    norm(A)1.39005
    min(svd(A))2.25289e-15
    cond(A)6.17007e+14
    rank(A)215
    null space dimension1
    full numerical rank?no
    singular value gap73.5274

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

    HB/gre_216b 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.