Matrix: DRIVCAV/cavity25

Description: Driven Cavity 20 x 20, Reynolds number: 900

DRIVCAV/cavity25 graph DRIVCAV/cavity25 graph
(bipartite graph drawing) (graph drawing of A+A')


DRIVCAV/cavity25 dmperm of DRIVCAV/cavity25
scc of DRIVCAV/cavity25

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  • Matrix group: DRIVCAV
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  • download as a MATLAB mat-file, file size: 915 KB. Use UFget(404) or UFget('DRIVCAV/cavity25') in MATLAB.
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    Matrix properties
    number of rows4,562
    number of columns4,562
    nonzeros131,735
    structural full rank?yes
    structural rank4,562
    # of blocks from dmperm322
    # strongly connected comp.322
    explicit zero entries6,452
    nonzero pattern symmetry 95%
    numeric value symmetry 0%
    typereal
    structureunsymmetric
    Cholesky candidate?no
    positive definite?no

    authorA. Chapman
    editorA. Baggag, Y. Saad
    date1996
    kindsubsequent computational fluid dynamics problem
    2D/3D problem?yes

    Additional fieldssize and type
    bfull 4562-by-1
    xfull 4562-by-1

    Notes:

    next: DRIVCAV/cavity26 first: DRIVCAV/cavity16          
    pattern is the same as the transpose of DRIVCAV/cavity16
    

    Ordering statistics:result
    nnz(chol(P*(A+A'+s*I)*P')) with AMD153,446
    Cholesky flop count9.1e+06
    nnz(L+U), no partial pivoting, with AMD302,330
    nnz(V) for QR, upper bound nnz(L) for LU, with COLAMD291,165
    nnz(R) for QR, upper bound nnz(U) for LU, with COLAMD943,772

    Note that all matrix statistics (except nonzero pattern symmetry) exclude the 6452 explicit zero entries.

    SVD-based statistics:
    norm(A)27.9078
    min(svd(A))1.01057e-06
    cond(A)2.76158e+07
    rank(A)4,562
    sprank(A)-rank(A)0
    null space dimension0
    full numerical rank?yes

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

    DRIVCAV/cavity25 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.