Matrix: GHS_indef/helm2d03

Description: Helmholtz eq. on a unit square: -div grad u -10000 u = 1, B.C. u = 0

GHS_indef/helm2d03 graph
(undirected graph drawing)

GHS_indef/helm2d03

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  • Matrix group: GHS_indef
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  • download as a MATLAB mat-file, file size: 8 MB. Use UFget(1236) or UFget('GHS_indef/helm2d03') in MATLAB.
  • download in Matrix Market format, file size: 9 MB.
  • download in Rutherford/Boeing format, file size: 7 MB.

    Matrix properties
    number of rows392,257
    number of columns392,257
    nonzeros2,741,935
    structural full rank?yes
    structural rank392,257
    # of blocks from dmperm1
    # strongly connected comp.1
    explicit zero entries0
    nonzero pattern symmetrysymmetric
    numeric value symmetrysymmetric
    typereal
    structuresymmetric
    Cholesky candidate?yes
    positive definite?no

    author
    editorN. Gould, Y. Hu, J. Scott
    date2004
    kind2D/3D problem
    2D/3D problem?yes

    Ordering statistics:result
    nnz(chol(P*(A+A'+s*I)*P')) with AMD28,433,335
    Cholesky flop count1.4e+10
    nnz(L+U), no partial pivoting, with AMD56,474,413
    nnz(V) for QR, upper bound nnz(L) for LU, with COLAMD46,657,690
    nnz(R) for QR, upper bound nnz(U) for LU, with COLAMD84,946,144

    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.