Matrix: ND/nd6k

Description: ND problem set, matrix nd6k

ND/nd6k graph
(undirected graph drawing)


  • Home page of the UF Sparse Matrix Collection
  • Matrix group: ND
  • Click here for a description of the ND group.
  • Click here for a list of all matrices
  • Click here for a list of all matrix groups
  • download as a MATLAB mat-file, file size: 50 MB. Use UFget(937) or UFget('ND/nd6k') in MATLAB.
  • download in Matrix Market format, file size: 27 MB.
  • download in Rutherford/Boeing format, file size: 21 MB.

    Matrix properties
    number of rows18,000
    number of columns18,000
    structural full rank?yes
    structural rank18,000
    # of blocks from dmperm1
    # strongly connected comp.1
    explicit zero entries0
    nonzero pattern symmetrysymmetric
    numeric value symmetrysymmetric
    Cholesky candidate?yes
    positive definite?yes

    authorauthor unknown
    editorT. Davis
    kind2D/3D problem
    2D/3D problem?yes

    Ordering statistics:result
    nnz(chol(P*(A+A'+s*I)*P')) with AMD51,202,639
    Cholesky flop count2.0e+11
    nnz(L+U), no partial pivoting, with AMD102,387,278
    nnz(V) for QR, upper bound nnz(L) for LU, with COLAMD48,412,972
    nnz(R) for QR, upper bound nnz(U) for LU, with COLAMD94,422,866

    SVD-based statistics:
    null space dimension0
    full numerical rank?yes

    singular values (MAT file):click here
    SVD method used:s = svd (full (A)) ;

    ND/nd6k svd

    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.