Matrix: TKK/tube2

Description: Tube problem from R. Kouhia

TKK/tube2 graph
(undirected graph drawing)


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  • Matrix group: TKK
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  • download as a MATLAB mat-file, file size: 251 KB. Use UFget(1915) or UFget('TKK/tube2') in MATLAB.
  • download in Matrix Market format, file size: 879 KB.
  • download in Rutherford/Boeing format, file size: 289 KB.

    Matrix properties
    number of rows21,498
    number of columns21,498
    structural full rank?yes
    structural rank21,498
    # of blocks from dmperm1
    # strongly connected comp.1
    explicit zero entries0
    nonzero pattern symmetrysymmetric
    numeric value symmetrysymmetric
    Cholesky candidate?yes
    positive definite?no

    authorR. Kouhia
    editorT. Davis
    kindstructural problem
    2D/3D problem?yes

    Additional fieldssize and type
    bfull 21498-by-1


    Matrix problems from Reijo Kouhia, Structural Mechanics, Helsinki  
    University of Technology.

    Ordering statistics:result
    nnz(chol(P*(A+A'+s*I)*P')) with AMD2,251,690
    Cholesky flop count4.6e+08
    nnz(L+U), no partial pivoting, with AMD4,481,882
    nnz(V) for QR, upper bound nnz(L) for LU, with COLAMD6,715,664
    nnz(R) for QR, upper bound nnz(U) for LU, with COLAMD12,198,788

    SVD-based statistics:
    null space dimension17,915
    full numerical rank?no
    singular value gap8.4176e+09

    singular values (MAT file):click here
    SVD method used:s = svd (full (R)) ; where [~,R,E] = spqr (A) with droptol of zero

    TKK/tube2 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.