Matrix: Rothberg/struct4

Description: Finite element matrix, from Ed Rothberg, Silicon Graphics, Inc.

Rothberg/struct4 graph
(undirected graph drawing)


Rothberg/struct4

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  • Matrix group: Rothberg
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  • download as a MATLAB mat-file, file size: 209 KB. Use UFget(808) or UFget('Rothberg/struct4') in MATLAB.
  • download in Matrix Market format, file size: 252 KB.
  • download in Rutherford/Boeing format, file size: 117 KB.

    Matrix properties
    number of rows4,350
    number of columns4,350
    nonzeros237,798
    structural full rank?yes
    structural rank4,350
    # of blocks from dmperm1
    # strongly connected comp.1
    explicit zero entries0
    nonzero pattern symmetrysymmetric
    numeric value symmetrysymmetric
    typebinary
    structuresymmetric
    Cholesky candidate?yes
    positive definite?no

    authorE. Rothberg
    editorT. Davis
    date1997
    kindstructural problem
    2D/3D problem?yes

    Ordering statistics:result
    nnz(chol(P*(A+A'+s*I)*P')) with AMD2,361,326
    Cholesky flop count2.0e+09
    nnz(L+U), no partial pivoting, with AMD4,718,302
    nnz(V) for QR, upper bound nnz(L) for LU, with COLAMD1,851,785
    nnz(R) for QR, upper bound nnz(U) for LU, with COLAMD3,321,077

    SVD-based statistics:
    norm(A)71.9473
    min(svd(A))0.000993909
    cond(A)72388.3
    rank(A)4,350
    sprank(A)-rank(A)0
    null space dimension0
    full numerical rank?yes

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

    Rothberg/struct4 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.