Matrix: HB/gre_512

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

HB/gre_512 graph HB/gre_512 graph
(bipartite graph drawing) (graph drawing of A+A')

HB/gre_512

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  • Matrix group: HB
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  • download as a MATLAB mat-file, file size: 5 KB. Use UFget(166) or UFget('HB/gre_512') in MATLAB.
  • download in Matrix Market format, file size: 7 KB.
  • download in Rutherford/Boeing format, file size: 6 KB.

    Matrix properties
    number of rows512
    number of columns512
    nonzeros1,976
    # strongly connected comp.1
    explicit zero entries216
    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 216 explicit zero entries.

    SVD-based statistics:
    norm(A)1.00835
    min(svd(A))0.00636913
    cond(A)158.318
    rank(A)512
    null space dimension0
    full numerical rank?yes

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

    HB/gre_512 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.