Matrix: GHS_indef/bloweybl

Description: MATRIX FOR WHICH EARLY VERSION OF MA57 FAILS

GHS_indef/bloweybl graph
(undirected graph drawing)


GHS_indef/bloweybl dmperm of GHS_indef/bloweybl
scc of GHS_indef/bloweybl

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  • Matrix group: GHS_indef
  • Click here for a description of the GHS_indef group.
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  • download as a MATLAB mat-file, file size: 186 KB. Use UFget(1424) or UFget('GHS_indef/bloweybl') in MATLAB.
  • download in Matrix Market format, file size: 193 KB.
  • download in Rutherford/Boeing format, file size: 150 KB.

    Matrix properties
    number of rows30,003
    number of columns30,003
    nonzeros109,999
    structural full rank?no
    structural rank30,002
    # of blocks from dmperm20,003
    # strongly connected comp.2
    explicit zero entries10,001
    nonzero pattern symmetrysymmetric
    numeric value symmetrysymmetric
    typereal
    structuresymmetric
    Cholesky candidate?no
    positive definite?no

    authorJ. Blowey
    editorN. Gould
    date1992
    kindmaterials problem
    2D/3D problem?yes

    Ordering statistics:result
    nnz(chol(P*(A+A'+s*I)*P')) with AMD99,999
    Cholesky flop count3.6e+05
    nnz(L+U), no partial pivoting, with AMD169,995
    nnz(V) for QR, upper bound nnz(L) for LU, with COLAMD79,992
    nnz(R) for QR, upper bound nnz(U) for LU, with COLAMD100,139,986

    Note that all matrix statistics (except nonzero pattern symmetry) exclude the 10001 explicit zero entries.

    SVD-based statistics:
    norm(A)100.008
    min(svd(A))4.33152e-19
    cond(A)2.30883e+20
    rank(A)20,028
    sprank(A)-rank(A)9,974
    null space dimension9,975
    full numerical rank?no
    singular value gap1.16396

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

    GHS_indef/bloweybl 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.