Matrix: Oberwolfach/gyro

Description: Oberwolfach: butterfly gyro

Oberwolfach/gyro graph
(undirected graph drawing)


Oberwolfach/gyro

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  • Matrix group: Oberwolfach
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  • download as a MATLAB mat-file, file size: 8 MB. Use UFget(1435) or UFget('Oberwolfach/gyro') in MATLAB.
  • download in Matrix Market format, file size: 7 MB.
  • download in Rutherford/Boeing format, file size: 6 MB.

    Matrix properties
    number of rows17,361
    number of columns17,361
    nonzeros1,021,159
    structural full rank?yes
    structural rank17,361
    # of blocks from dmperm1
    # strongly connected comp.1
    explicit zero entries0
    nonzero pattern symmetrysymmetric
    numeric value symmetrysymmetric
    typereal
    structuresymmetric
    Cholesky candidate?yes
    positive definite?yes

    authorD. Billger
    editorE. Rudnyi
    date2004
    kindmodel reduction problem
    2D/3D problem?yes

    Additional fieldssize and type
    Msparse 17361-by-17361
    Bsparse 17361-by-1
    Csparse 12-by-17361
    cnamefull 12-by-7

    Notes:

    Primary matrix in this model reduction problem is the Oberwolfach K matrix
    

    Ordering statistics:result
    nnz(chol(P*(A+A'+s*I)*P')) with AMD1,232,355
    Cholesky flop count1.2e+08
    nnz(L+U), no partial pivoting, with AMD2,447,349
    nnz(V) for QR, upper bound nnz(L) for LU, with COLAMD3,282,796
    nnz(R) for QR, upper bound nnz(U) for LU, with COLAMD10,285,290

    SVD-based statistics:
    norm(A)3.65695e+09
    min(svd(A))3.33715
    cond(A)1.09583e+09
    rank(A)17,361
    sprank(A)-rank(A)0
    null space dimension0
    full numerical rank?yes

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

    Oberwolfach/gyro 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.