Matrix: HB/nos6

Description: SYMMETRIC MATRIX, POISSON'S EQUATION IN L SHAPE, MIXED BC.

HB/nos6 graph
(undirected graph drawing)


HB/nos6

  • 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: 6 KB. Use UFget(222) or UFget('HB/nos6') in MATLAB.
  • download in Matrix Market format, file size: 7 KB.
  • download in Rutherford/Boeing format, file size: 6 KB.

    Matrix properties
    number of rows675
    number of columns675
    nonzeros3,255
    structural full rank?yes
    structural rank675
    # of blocks from dmperm1
    # strongly connected comp.1
    explicit zero entries0
    nonzero pattern symmetrysymmetric
    numeric value symmetrysymmetric
    typereal
    structuresymmetric
    Cholesky candidate?yes
    positive definite?yes

    authorH. Simon
    editorI. Duff, R. Grimes, J. Lewis
    date1982
    kind2D/3D problem
    2D/3D problem?yes

    Ordering statistics:result
    nnz(chol(P*(A+A'+s*I)*P')) with AMD6,453
    Cholesky flop count8.6e+04
    nnz(L+U), no partial pivoting, with AMD12,231
    nnz(V) for QR, upper bound nnz(L) for LU, with COLAMD9,264
    nnz(R) for QR, upper bound nnz(U) for LU, with COLAMD16,906

    SVD-based statistics:
    norm(A)7.6506e+06
    min(svd(A))1.00002
    cond(A)7.65049e+06
    rank(A)675
    sprank(A)-rank(A)0
    null space dimension0
    full numerical rank?yes

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

    HB/nos6 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.