• 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-71
  • Description: Schenk: IBM TJ Watson, Yorktown, nonlinear optimization
  • download as a MATLAB mat-file, file size: 5 MB. Use UFget(1228) or UFget('GHS_indef/c-71') in MATLAB.
  • download in Matrix Market format
  • download in Rutherford/Boeing format

    GHS_indef/c-71

    dmperm of GHS_indef/c-71

    GHS_indef/c-71 graph

    Matrix properties
    number of rows76,638
    number of columns76,638
    nonzeros859,520
    structural full rank?yes
    structural rank76,638
    # of blocks from dmperm18
    # strongly connected comp.18
    entries not in dmperm blocks51
    explicit zero entries34
    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 76638-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'))19,945,308 12,458,222 12,465,479
    Cholesky flop count5.7e+10 1.8e+10 1.8e+10
    nnz(L+U), no partial pivoting39,813,978 24,839,806 24,854,371
    nnz(V) for QR, upper bound nnz(L) for LU128,102,620 - 128,102,586
    nnz(R) for QR, upper bound nnz(U) for LU201,580,038 - 201,580,055

    Note that all matrix statistics (except nonzero pattern symmetry) exclude the 34 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.