Matrix: Li/li

Description: 3D Finite element matrix, magnetohydrodynamic problem with 5 variables

Li/li graph
(undirected graph drawing)

Li/li dmperm of Li/li

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  • Matrix group: Li
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  • download as a MATLAB mat-file, file size: 5 MB. Use UFget(732) or UFget('Li/li') in MATLAB.
  • download in Matrix Market format, file size: 10 MB.
  • download in Rutherford/Boeing format, file size: 8 MB.

    Matrix properties
    number of rows22,695
    number of columns22,695
    structural full rank?yes
    structural rank22,695
    # of blocks from dmperm4
    # strongly connected comp.4
    explicit zero entries135,128
    nonzero pattern symmetrysymmetric
    numeric value symmetry 87%
    Cholesky candidate?no
    positive definite?no

    authorB. Li
    editorT. Davis
    kindelectromagnetics problem
    2D/3D problem?yes

    Ordering statistics:result
    nnz(chol(P*(A+A'+s*I)*P')) with AMD30,408,095
    Cholesky flop count7.9e+10
    nnz(L+U), no partial pivoting, with AMD60,793,495
    nnz(V) for QR, upper bound nnz(L) for LU, with COLAMD33,668,257
    nnz(R) for QR, upper bound nnz(U) for LU, with COLAMD56,815,640

    Note that all matrix statistics (except nonzero pattern symmetry) exclude the 135128 explicit zero entries.

    SVD-based statistics:
    null space dimension55
    full numerical rank?no
    singular value gap1.02609

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

    Li/li 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.