Matrix: HB/steam2

Description: UNSYMMETRIC - 3D STEAM MODEL OF OIL RES. - 5 X 5 X 6 - 4 DOF MAY 1983

HB/steam2 graph
(undirected graph drawing)


HB/steam2 dmperm of HB/steam2

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  • Matrix group: HB
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  • download as a MATLAB mat-file, file size: 37 KB. Use UFget(252) or UFget('HB/steam2') in MATLAB.
  • download in Matrix Market format, file size: 54 KB.
  • download in Rutherford/Boeing format, file size: 30 KB.

    Matrix properties
    number of rows600
    number of columns600
    nonzeros5,660
    structural full rank?yes
    structural rank600
    # of blocks from dmperm151
    # strongly connected comp.151
    explicit zero entries8,100
    nonzero pattern symmetrysymmetric
    numeric value symmetry 19%
    typereal
    structureunsymmetric
    Cholesky candidate?no
    positive definite?no

    authorR. Grimes
    editorI. Duff, R. Grimes, J. Lewis
    date1983
    kindcomputational fluid dynamics problem
    2D/3D problem?yes

    Ordering statistics:result
    nnz(chol(P*(A+A'+s*I)*P')) with AMD21,336
    Cholesky flop count1.2e+06
    nnz(L+U), no partial pivoting, with AMD42,072
    nnz(V) for QR, upper bound nnz(L) for LU, with COLAMD23,112
    nnz(R) for QR, upper bound nnz(U) for LU, with COLAMD43,622

    Note that all matrix statistics (except nonzero pattern symmetry) exclude the 8100 explicit zero entries.

    SVD-based statistics:
    norm(A)4.6856e+09
    min(svd(A))1238.55
    cond(A)3.78313e+06
    rank(A)600
    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/steam2 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.