Matrix: HB/gr_30_30

Description: SYMMETRIC MATRIX FROM NINE POINT START ON A 30 X 30 GRID.

HB/gr_30_30 graph
(undirected graph drawing)


HB/gr_30_30

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  • Matrix group: HB
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  • download as a MATLAB mat-file, file size: 7 KB. Use UFget(159) or UFget('HB/gr_30_30') in MATLAB.
  • download in Matrix Market format, file size: 11 KB.
  • download in Rutherford/Boeing format, file size: 7 KB.

    Matrix properties
    number of rows900
    number of columns900
    nonzeros7,744
    structural full rank?yes
    structural rank900
    # of blocks from dmperm1
    # strongly connected comp.1
    explicit zero entries0
    nonzero pattern symmetrysymmetric
    numeric value symmetrysymmetric
    typeinteger
    structuresymmetric
    Cholesky candidate?yes
    positive definite?yes

    authorR. Grimes
    editorI. Duff, R. Grimes, J. Lewis
    date1983
    kind2D/3D problem
    2D/3D problem?yes

    Ordering statistics:result
    nnz(chol(P*(A+A'+s*I)*P')) with AMD16,348
    Cholesky flop count4.1e+05
    nnz(L+U), no partial pivoting, with AMD31,796
    nnz(V) for QR, upper bound nnz(L) for LU, with COLAMD24,382
    nnz(R) for QR, upper bound nnz(U) for LU, with COLAMD44,942

    SVD-based statistics:
    norm(A)11.9591
    min(svd(A))0.0614628
    cond(A)194.574
    rank(A)900
    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/gr_30_30 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.