• UF Sparse Matrix Collection
  • Matrix group: GHS_psdef
  • Click here for a description of the GHS_psdef group.
  • Click here for a list of all matrices
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  • Matrix: GHS_psdef/apache2
  • Description: SPD matrix (finite difference 3D) from APACHE small
  • download as a MATLAB mat-file, file size: 8 MB. Use UFget(1423) or UFget('GHS_psdef/apache2') in MATLAB.
  • download in Matrix Market format
  • download in Rutherford/Boeing format

    GHS_psdef/apache2

    GHS_psdef/apache2 graph

    Matrix properties
    number of rows715,176
    number of columns715,176
    nonzeros4,817,870
    structural full rank?yes
    structural rank715,176
    # of blocks from dmperm1
    # strongly connected comp.1
    entries not in dmperm blocks0
    explicit zero entries0
    nonzero pattern symmetrysymmetric
    numeric value symmetrysymmetric
    typereal
    structuresymmetric
    Cholesky candidate?yes
    positive definite?yes

    author
    editorN. Gould, Y. Hu, J. Scott
    date2006
    kindstructural problem
    2D/3D problem?yes

    Ordering statistics:AMD METIS
    nnz(chol(P*(A+A'+s*I)*P'))177,279,446 137,848,105
    Cholesky flop count2.8e+11 1.9e+11
    nnz(L+U), no partial pivoting353,843,716 274,981,034
    nnz(V) for QR, upper bound nnz(L) for LU401,332,351 276,048,774
    nnz(R) for QR, upper bound nnz(U) for LU733,526,338 506,251,375

    Maintained by Tim Davis, last updated 04-May-2008.
    Matrix pictures by cspy, a MATLAB function in the CSparse package.
    Matrix graphs by Yifan Hu, AT&T Labs Visualization Group.