Matrix: GHS_psdef/apache1

Description: SPD matrix (finite difference 3D) from APACHE small

GHS_psdef/apache1 graph
(undirected graph drawing)


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  • Matrix group: GHS_psdef
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  • download as a MATLAB mat-file, file size: 986 KB. Use UFget(1422) or UFget('GHS_psdef/apache1') in MATLAB.
  • download in Matrix Market format, file size: 1004 KB.
  • download in Rutherford/Boeing format, file size: 864 KB.

    Matrix properties
    number of rows80,800
    number of columns80,800
    structural full rank?yes
    structural rank80,800
    # of blocks from dmperm1
    # strongly connected comp.1
    explicit zero entries0
    nonzero pattern symmetrysymmetric
    numeric value symmetrysymmetric
    Cholesky candidate?yes
    positive definite?yes

    editorN. Gould, Y. Hu, J. Scott
    kindstructural problem
    2D/3D problem?yes

    Ordering statistics:result
    nnz(chol(P*(A+A'+s*I)*P')) with AMD12,720,302
    Cholesky flop count8.4e+09
    nnz(L+U), no partial pivoting, with AMD25,359,804
    nnz(V) for QR, upper bound nnz(L) for LU, with COLAMD28,420,466
    nnz(R) for QR, upper bound nnz(U) for LU, with COLAMD51,283,650

    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.