• UF Sparse Matrix Collection
  • Matrix group: MathWorks
  • Click here for a description of the MathWorks group.
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  • Matrix: MathWorks/Sieber
  • Description: Default tol and symtol not sufficient. Jan Sieber, Univ Bristol
  • download as a MATLAB mat-file, file size: 100 KB. Use UFget(1378) or UFget('MathWorks/Sieber') in MATLAB.
  • download in Matrix Market format
  • download in Rutherford/Boeing format

    MathWorks/Sieber

    MathWorks/Sieber graph

    Matrix properties
    number of rows2,290
    number of columns2,290
    nonzeros14,873
    structural full rank?yes
    structural rank2,290
    # of blocks from dmperm1
    # strongly connected comp.1
    entries not in dmperm blocks0
    explicit zero entries0
    nonzero pattern symmetry 73%
    numeric value symmetry 0%
    typereal
    structureunsymmetric
    Cholesky candidate?no
    positive definite?no

    authorSieber
    editorT. Davis
    date2006
    kindcounter-example problem
    2D/3D problem?no

    Additional fieldssize and type
    bfull 2290-by-1

    Ordering statistics:AMD METIS
    nnz(chol(P*(A+A'+s*I)*P'))16,008 14,913
    Cholesky flop count1.1e+05 9.8e+04
    nnz(L+U), no partial pivoting29,726 27,536
    nnz(V) for QR, upper bound nnz(L) for LU11,441 11,440
    nnz(R) for QR, upper bound nnz(U) for LU2,623,195 2,623,195

    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.