Matrix: GHS_indef/stokes64

Description: Gould, Hu, & Scott: Stokes equation, from Mario Arioli

GHS_indef/stokes64 graph
(undirected graph drawing)


GHS_indef/stokes64

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  • Matrix group: GHS_indef
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  • download as a MATLAB mat-file, file size: 285 KB. Use UFget(1247) or UFget('GHS_indef/stokes64') in MATLAB.
  • download in Matrix Market format, file size: 336 KB.
  • download in Rutherford/Boeing format, file size: 225 KB.

    Matrix properties
    number of rows12,546
    number of columns12,546
    nonzeros140,034
    structural full rank?yes
    structural rank12,546
    # of blocks from dmperm1
    # strongly connected comp.1
    explicit zero entries0
    nonzero pattern symmetrysymmetric
    numeric value symmetrysymmetric
    typereal
    structuresymmetric
    Cholesky candidate?no
    positive definite?no

    authorM. Arioli
    editorN. Gould, Y. Hu, J. Scott
    date2004
    kindcomputational fluid dynamics problem
    2D/3D problem?yes

    Ordering statistics:result
    nnz(chol(P*(A+A'+s*I)*P')) with AMD487,299
    Cholesky flop count4.3e+07
    nnz(L+U), no partial pivoting, with AMD962,052
    nnz(V) for QR, upper bound nnz(L) for LU, with COLAMD1,046,650
    nnz(R) for QR, upper bound nnz(U) for LU, with COLAMD2,348,996

    SVD-based statistics:
    norm(A)3.99785
    min(svd(A))7.49251e-17
    cond(A)5.3358e+16
    rank(A)12,544
    sprank(A)-rank(A)2
    null space dimension2
    full numerical rank?no
    singular value gap1.92936e+09

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

    GHS_indef/stokes64 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.