Matrix: Schenk_IBMNA/c-20

Description: IBM TJ Watson, non-linear optimization

Schenk_IBMNA/c-20 graph
(undirected graph drawing)


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  • Matrix group: Schenk_IBMNA
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  • download as a MATLAB mat-file, file size: 118 KB. Use UFget(1539) or UFget('Schenk_IBMNA/c-20') in MATLAB.
  • download in Matrix Market format, file size: 103 KB.
  • download in Rutherford/Boeing format, file size: 94 KB.

    Matrix properties
    number of rows2,921
    number of columns2,921
    structural full rank?yes
    structural rank2,921
    # of blocks from dmperm1
    # strongly connected comp.1
    explicit zero entries2,240
    nonzero pattern symmetrysymmetric
    numeric value symmetrysymmetric
    Cholesky candidate?no
    positive definite?no

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

    Additional fieldssize and type
    bfull 2921-by-1

    Ordering statistics:result
    nnz(chol(P*(A+A'+s*I)*P')) with AMD22,778
    Cholesky flop count6.2e+05
    nnz(L+U), no partial pivoting, with AMD42,635
    nnz(V) for QR, upper bound nnz(L) for LU, with COLAMD122,244
    nnz(R) for QR, upper bound nnz(U) for LU, with COLAMD225,453

    Note that all matrix statistics (except nonzero pattern symmetry) exclude the 2240 explicit zero entries.

    SVD-based statistics:
    null space dimension0
    full numerical rank?yes

    singular values (MAT file):click here
    SVD method used:s = svd (full (A)) ;

    Schenk_IBMNA/c-20 svd

    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.