• UF Sparse Matrix Collection
  • Matrix group: GHS_indef
  • Click here for a description of the GHS_indef group.
  • Click here for a list of all matrices
  • Click here for a list of all matrix groups

  • Matrix: GHS_indef/c-62ghs
  • Description: Gould,Hu,Scott: nearly same pattern as Schenk_IBMNA/c-62, diff. values
  • download as a MATLAB mat-file, file size: 3 MB. Use UFget(1223) or UFget('GHS_indef/c-62ghs') in MATLAB.
  • download in Matrix Market format
  • download in Rutherford/Boeing format

    GHS_indef/c-62ghs

    dmperm of GHS_indef/c-62ghs

    GHS_indef/c-62ghs graph

    Matrix properties
    number of rows41,731
    number of columns41,731
    nonzeros559,339
    structural full rank?yes
    structural rank41,731
    # of blocks from dmperm3
    # strongly connected comp.3
    entries not in dmperm blocks6
    explicit zero entries4
    nonzero pattern symmetrysymmetric
    numeric value symmetrysymmetric
    typereal
    structuresymmetric
    Cholesky candidate?no
    positive definite?no

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

    Additional fieldssize and type
    bfull 41731-by-1

    Notes:

    next: - first: Schenk_IBMNA/c-62                                       
A version of this matrix was first obtained from Olaf Schenk in October
2003.  That version appears in this collection as Schenk_IBMNA/c-62.   
In August 2004, a new version appeared in the GHS collection, under the
same name, and was added here as GHS_indef/c-62ghs.  The c-62ghs matrix
is the same as the version on Schenk's web site as of Nov 2006, except 
that the right-hand-side was missing in the version in the UF Sparse   
Matrix Collection (now included).  The two matrices c-62 and c-62ghs   
are very similar, but not identical.

    Ordering statistics:AMD METIS DMPERM+
    nnz(chol(P*(A+A'+s*I)*P'))9,819,875 6,666,296 6,721,604
    Cholesky flop count1.7e+10 6.8e+09 7.0e+09
    nnz(L+U), no partial pivoting19,598,019 13,290,861 13,401,483
    nnz(V) for QR, upper bound nnz(L) for LU56,979,641 40,702,087 39,944,328
    nnz(R) for QR, upper bound nnz(U) for LU87,542,190 79,130,050 81,072,571

    Note that all matrix statistics (except nonzero pattern symmetry) exclude the 4 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.