Matrix: GHS_indef/linverse

Description: Gould, Hu, & Scott: matrix inverse approximation (CUTEr)

GHS_indef/linverse graph
(undirected graph drawing)


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  • Matrix group: GHS_indef
  • Click here for a description of the GHS_indef group.
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  • download as a MATLAB mat-file, file size: 520 KB. Use UFget(1303) or UFget('GHS_indef/linverse') in MATLAB.
  • download in Matrix Market format, file size: 656 KB.
  • download in Rutherford/Boeing format, file size: 601 KB.

    Matrix properties
    number of rows11,999
    number of columns11,999
    structural full rank?yes
    structural rank11,999
    # of blocks from dmperm1
    # strongly connected comp.1
    explicit zero entries0
    nonzero pattern symmetrysymmetric
    numeric value symmetrysymmetric
    Cholesky candidate?yes
    positive definite?no

    authorP. Toint
    editorP. Toint
    kindstatistical/mathematical problem
    2D/3D problem?no

    Ordering statistics:result
    nnz(chol(P*(A+A'+s*I)*P')) with AMD53,988
    Cholesky flop count2.5e+05
    nnz(L+U), no partial pivoting, with AMD95,977
    nnz(V) for QR, upper bound nnz(L) for LU, with COLAMD54,000
    nnz(R) for QR, upper bound nnz(U) for LU, with COLAMD101,960

    SVD-based statistics:
    null space dimension0
    full numerical rank?yes

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

    GHS_indef/linverse 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.