Matrix: Nasa/skirt

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

Nasa/skirt graph
(undirected graph drawing)

Nasa/skirt dmperm of Nasa/skirt

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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: 190 KB. Use UFget(764) or UFget('Nasa/skirt') in MATLAB.
  • download in Matrix Market format, file size: 222 KB.
  • download in Rutherford/Boeing format, file size: 145 KB.

    Matrix properties
    number of rows12,598
    number of columns12,598
    structural full rank?yes
    structural rank12,598
    # of blocks from dmperm7
    # strongly connected comp.7
    explicit zero entries0
    nonzero pattern symmetrysymmetric
    numeric value symmetrysymmetric
    Cholesky candidate?yes
    positive definite?no

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


    Identical to Pothen/skirt; the latter has xyz coordinates.

    Ordering statistics:result
    nnz(chol(P*(A+A'+s*I)*P')) with AMD480,579
    Cholesky flop count3.4e+07
    nnz(L+U), no partial pivoting, with AMD948,560
    nnz(V) for QR, upper bound nnz(L) for LU, with COLAMD826,916
    nnz(R) for QR, upper bound nnz(U) for LU, with COLAMD1,528,684

    SVD-based statistics:
    null space dimension2,767
    full numerical rank?no
    singular value gap1.45452e+09

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

    Nasa/skirt 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.