Matrix: GHS_indef/c-62ghs

Description: Gould,Hu,Scott: nearly same pattern as Schenk_IBMNA/c-62, diff. values

GHS_indef/c-62ghs graph
(undirected graph drawing)

GHS_indef/c-62ghs dmperm of GHS_indef/c-62ghs

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  • Matrix group: GHS_indef
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  • 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, file size: 2 MB.
  • download in Rutherford/Boeing format, file size: 2 MB.

    Matrix properties
    number of rows41,731
    number of columns41,731
    structural full rank?yes
    structural rank41,731
    # of blocks from dmperm3
    # strongly connected comp.3
    explicit zero entries4
    nonzero pattern symmetrysymmetric
    numeric value symmetrysymmetric
    Cholesky candidate?no
    positive definite?no

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

    Additional fieldssize and type
    bfull 41731-by-1


    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:result
    nnz(chol(P*(A+A'+s*I)*P')) with AMD9,819,875
    Cholesky flop count1.7e+10
    nnz(L+U), no partial pivoting, with AMD19,598,019
    nnz(V) for QR, upper bound nnz(L) for LU, with COLAMD125,385,616
    nnz(R) for QR, upper bound nnz(U) for LU, with COLAMD173,361,037

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