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


  • Matrix: Gset/G31
  • Description: Random matrix, 1% uniformly distributed. G26=pattern of G31
  • download as a MATLAB mat-file, file size: 92 KB. Use UFget(493) or UFget('Gset/G31') in MATLAB.
  • download in Matrix Market format
  • download in Rutherford/Boeing format

    Gset/G31

    Gset/G31 graph

    Matrix properties
    number of rows2,000
    number of columns2,000
    nonzeros39,980
    structural full rank?yes
    structural rank2,000
    # of blocks from dmperm1
    # strongly connected comp.1
    entries not in dmperm blocks0
    explicit zero entries0
    nonzero pattern symmetrysymmetric
    numeric value symmetrysymmetric
    typeinteger
    structuresymmetric
    Cholesky candidate?yes
    positive definite?no

    authorC. Helmberg
    editorY. Ye
    date1996
    kindundirected weighted random graph
    2D/3D problem?no

    Ordering statistics:AMD METIS
    nnz(chol(P*(A+A'+s*I)*P'))975,262 1,069,294
    Cholesky flop count8.6e+08 9.9e+08
    nnz(L+U), no partial pivoting1,948,524 2,136,588
    nnz(V) for QR, upper bound nnz(L) for LU1,715,700 1,653,664
    nnz(R) for QR, upper bound nnz(U) for LU1,875,211 1,902,431

    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.