• UF Sparse Matrix Collection
  • Matrix group: GHS_indef
  • Click here for a description of the GHS_indef group.
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  • Matrix: GHS_indef/c-68
  • Description: Schenk: IBM TJ Watson, Yorktown, nonlinear optimization
  • download as a MATLAB mat-file, file size: 3 MB. Use UFget(1225) or UFget('GHS_indef/c-68') in MATLAB.
  • download in Matrix Market format
  • download in Rutherford/Boeing format

    GHS_indef/c-68

    dmperm of GHS_indef/c-68

    GHS_indef/c-68 graph

    Matrix properties
    number of rows64,810
    number of columns64,810
    nonzeros565,996
    structural full rank?yes
    structural rank64,810
    # of blocks from dmperm6
    # strongly connected comp.6
    entries not in dmperm blocks15
    explicit zero entries10
    nonzero pattern symmetrysymmetric
    numeric value symmetrysymmetric
    typereal
    structuresymmetric
    Cholesky candidate?no
    positive definite?no

    authorIBM
    editorO. Schenk
    date2004
    kindoptimization problem
    2D/3D problem?no

    Additional fieldssize and type
    bfull 64810-by-1

    Notes:

    Revised Nov 2006; relative eps changes to A, right-hand-side added.
    Note that this matrix should have been placed in the Schenk_IBMNA/ 
    directory when it was first added in August 2004, but moving it now
    would disrupt exising users of the collection.                     
    

    Ordering statistics:AMD METIS DMPERM+
    nnz(chol(P*(A+A'+s*I)*P'))6,523,400 5,144,147 5,413,032
    Cholesky flop count1.2e+10 5.0e+09 5.5e+09
    nnz(L+U), no partial pivoting12,981,990 10,223,484 10,761,269
    nnz(V) for QR, upper bound nnz(L) for LU70,689,995 36,068,324 34,302,462
    nnz(R) for QR, upper bound nnz(U) for LU115,405,123 72,517,805 71,813,196

    Note that all matrix statistics (except nonzero pattern symmetry) exclude the 10 explicit zero entries.

    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.