Matrix: HB/steam1

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

HB/steam1 graph
(undirected graph drawing)


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  • Matrix group: HB
  • Click here for a description of the HB group.
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  • download as a MATLAB mat-file, file size: 15 KB. Use UFget(251) or UFget('HB/steam1') in MATLAB.
  • download in Matrix Market format, file size: 18 KB.
  • download in Rutherford/Boeing format, file size: 12 KB.

    Matrix properties
    number of rows240
    number of columns240
    structural full rank?yes
    structural rank240
    # of blocks from dmperm1
    # strongly connected comp.1
    explicit zero entries1,514
    nonzero pattern symmetrysymmetric
    numeric value symmetry 27%
    Cholesky candidate?no
    positive definite?no

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

    Ordering statistics:result
    nnz(chol(P*(A+A'+s*I)*P')) with AMD5,128
    Cholesky flop count1.6e+05
    nnz(L+U), no partial pivoting, with AMD10,016
    nnz(V) for QR, upper bound nnz(L) for LU, with COLAMD4,691
    nnz(R) for QR, upper bound nnz(U) for LU, with COLAMD8,498

    Note that all matrix statistics (except nonzero pattern symmetry) exclude the 1514 explicit zero entries.

    SVD-based statistics:
    null space dimension0
    full numerical rank?yes

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

    HB/steam1 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.