Matrix: HB/jgl011

Description: U JOHN G. LEWIS P4 COUNTEREXAMPLE WHICH REQUIRES FILL IN SPIKES

HB/jgl011 graph HB/jgl011 graph
(bipartite graph drawing) (graph drawing of A+A')


HB/jgl011

  • Home page of the UF Sparse Matrix Collection
  • Matrix group: HB
  • Click here for a description of the HB 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: 531 bytes. Use UFget(186) or UFget('HB/jgl011') in MATLAB.
  • download in Matrix Market format, file size: 590 bytes.
  • download in Rutherford/Boeing format, file size: 551 bytes.

    Matrix properties
    number of rows11
    number of columns11
    nonzeros76
    structural full rank?yes
    structural rank11
    # of blocks from dmperm1
    # strongly connected comp.1
    explicit zero entries0
    nonzero pattern symmetry 52%
    numeric value symmetry 52%
    typebinary
    structureunsymmetric
    Cholesky candidate?no
    positive definite?no

    authorJ. Lewis
    editorI. Duff, R. Grimes, J. Lewis
    date1983
    kindcounter-example problem
    2D/3D problem?no

    Ordering statistics:result
    nnz(chol(P*(A+A'+s*I)*P')) with AMD60
    Cholesky flop count4.1e+02
    nnz(L+U), no partial pivoting, with AMD109
    nnz(V) for QR, upper bound nnz(L) for LU, with COLAMD47
    nnz(R) for QR, upper bound nnz(U) for LU, with COLAMD66

    SVD-based statistics:
    norm(A)7.69495
    min(svd(A))0
    cond(A)Inf
    rank(A)5
    sprank(A)-rank(A)6
    null space dimension6
    full numerical rank?no
    singular value gap3.92602e+15

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

    HB/jgl011 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.