Matrix: HB/bcsstk27

Description: STIFFNESS MATRIX BUCKLING PROBLEM (ANDY MERA)

HB/bcsstk27 graph
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HB/bcsstk27

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  • Matrix group: HB
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  • download as a MATLAB mat-file, file size: 397 KB. Use UFget(49) or UFget('HB/bcsstk27') in MATLAB.
  • download in Matrix Market format, file size: 315 KB.
  • download in Rutherford/Boeing format, file size: 267 KB.

    Matrix properties
    number of rows1,224
    number of columns1,224
    nonzeros56,126
    structural full rank?yes
    structural rank1,224
    # of blocks from dmperm1
    # strongly connected comp.1
    explicit zero entries0
    nonzero pattern symmetrysymmetric
    numeric value symmetrysymmetric
    typereal
    structuresymmetric
    Cholesky candidate?yes
    positive definite?yes

    authorA. Mera, R. Cigel, J. Lewis
    editorI. Duff, R. Grimes, J. Lewis
    date1984
    kindstructural problem
    2D/3D problem?yes

    Ordering statistics:result
    nnz(chol(P*(A+A'+s*I)*P')) with AMD55,749
    Cholesky flop count2.7e+06
    nnz(L+U), no partial pivoting, with AMD110,274
    nnz(V) for QR, upper bound nnz(L) for LU, with COLAMD51,864
    nnz(R) for QR, upper bound nnz(U) for LU, with COLAMD95,606

    SVD-based statistics:
    norm(A)3.46506e+06
    min(svd(A))143.565
    cond(A)24135.9
    rank(A)1,224
    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/bcsstk27 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.