Matrix: Nasa/barth

Description: BARTH: Nasa matrix, but with a diagonal added to the original

Nasa/barth graph Nasa/barth graph
(bipartite graph drawing) (graph drawing of A+A')

Nasa/barth dmperm of Nasa/barth

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  • Matrix group: Nasa
  • Click here for a description of the Nasa group.
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  • download as a MATLAB mat-file, file size: 70 KB. Use UFget(754) or UFget('Nasa/barth') in MATLAB.
  • download in Matrix Market format, file size: 94 KB.
  • download in Rutherford/Boeing format, file size: 72 KB.

    Matrix properties
    number of rows6,691
    number of columns6,691
    nonzeros26,439
    structural full rank?yes
    structural rank6,691
    # of blocks from dmperm981
    # strongly connected comp.981
    explicit zero entries0
    nonzero pattern symmetry 0%
    numeric value symmetry 0%
    typebinary
    structureunsymmetric
    Cholesky candidate?no
    positive definite?no

    authorNASA
    editorG. Kumfert, A. Pothen
    date1995
    kindduplicate structural problem
    2D/3D problem?yes

    Notes:

    Let A=Nasa/barth, then Pothen/barth = spones(A+A') with xyz coord.

    Ordering statistics:result
    nnz(chol(P*(A+A'+s*I)*P')) with AMD109,795
    Cholesky flop count4.0e+06
    nnz(L+U), no partial pivoting, with AMD212,899
    nnz(V) for QR, upper bound nnz(L) for LU, with COLAMD66,621
    nnz(R) for QR, upper bound nnz(U) for LU, with COLAMD155,857

    SVD-based statistics:
    norm(A)4.89284
    min(svd(A))6.71538e-17
    cond(A)7.28602e+16
    rank(A)6,690
    sprank(A)-rank(A)1
    null space dimension1
    full numerical rank?no
    singular value gap8.8042e+10

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

    Nasa/barth 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.