Matrix: Schenk_IBMNA/c-66b

Description: IBM TJ Watson, non-linear optimization

Schenk_IBMNA/c-66b graph
(undirected graph drawing)


Schenk_IBMNA/c-66b dmperm of Schenk_IBMNA/c-66b

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  • download as a MATLAB mat-file, file size: 2 MB. Use UFget(1588) or UFget('Schenk_IBMNA/c-66b') in MATLAB.
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    Matrix properties
    number of rows49,989
    number of columns49,989
    nonzeros444,851
    structural full rank?yes
    structural rank49,989
    # of blocks from dmperm7
    # strongly connected comp.7
    explicit zero entries54,156
    nonzero pattern symmetrysymmetric
    numeric value symmetrysymmetric
    typereal
    structuresymmetric
    Cholesky candidate?no
    positive definite?no

    authorIBM
    editorO. Schenk
    date2006
    kindsubsequent optimization problem
    2D/3D problem?no

    Additional fieldssize and type
    bfull 49989-by-1

    Notes:

    next: - first: Schenk_IBMNA/c-66                                       
    An earlier version (Oct. 2003) of this matrix was obtained from Olaf   
    Schenk, and appears here as Schenk_IBMNA/c-66.  However, it differs    
    from the version posted on his web site as of Nov. 2006.   The new     
    version appears here as Schenk_IBMNA/c-66b.   The two matrices are very
    similar, but not identical.                                            
    

    Ordering statistics:result
    nnz(chol(P*(A+A'+s*I)*P')) with AMD1,009,418
    Cholesky flop count2.7e+08
    nnz(L+U), no partial pivoting, with AMD1,968,847
    nnz(V) for QR, upper bound nnz(L) for LU, with COLAMD79,558,462
    nnz(R) for QR, upper bound nnz(U) for LU, with COLAMD174,206,767

    Note that all matrix statistics (except nonzero pattern symmetry) exclude the 54156 explicit zero entries.

    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.