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


  • Matrix: DNVS/troll
  • Description: Gould, Hu, & Scott: from Christian Damhaug
  • download as a MATLAB mat-file, file size: 4 MB. Use UFget(1285) or UFget('DNVS/troll') in MATLAB.
  • download in Matrix Market format
  • download in Rutherford/Boeing format

    DNVS/troll

    DNVS/troll graph

    Matrix properties
    number of rows213,453
    number of columns213,453
    nonzeros11,985,111
    structural full rank?yes
    structural rank213,453
    # of blocks from dmperm1
    # strongly connected comp.1
    entries not in dmperm blocks0
    explicit zero entries0
    nonzero pattern symmetrysymmetric
    numeric value symmetrysymmetric
    typebinary
    structuresymmetric
    Cholesky candidate?yes
    positive definite?no

    authorC. Damhaug
    editorN. Gould, Y. Hu, J. Scott
    date2004
    kindstructural problem
    2D/3D problem?yes

    Ordering statistics:AMD METIS
    nnz(chol(P*(A+A'+s*I)*P'))91,897,326 64,791,897
    Cholesky flop count1.6e+11 5.7e+10
    nnz(L+U), no partial pivoting183,581,199 129,370,341
    nnz(V) for QR, upper bound nnz(L) for LU245,556,264 137,136,825
    nnz(R) for QR, upper bound nnz(U) for LU464,144,670 256,992,516

    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.