Matrix: HB/lund_a

Description: SYMMETRIC MATRIX A OF LUND EIGENVALUE PROBLEM, MAY 1974

HB/lund_a graph
(undirected graph drawing)


HB/lund_a

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  • Matrix group: HB
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  • download as a MATLAB mat-file, file size: 6 KB. Use UFget(206) or UFget('HB/lund_a') in MATLAB.
  • download in Matrix Market format, file size: 6 KB.
  • download in Rutherford/Boeing format, file size: 4 KB.

    Matrix properties
    number of rows147
    number of columns147
    nonzeros2,449
    structural full rank?yes
    structural rank147
    # 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

    authorT. Johansson
    editorA. Curtis, I. Duff, J. Reid
    date1974
    kindstructural problem
    2D/3D problem?yes

    Ordering statistics:result
    nnz(chol(P*(A+A'+s*I)*P')) with AMD2,339
    Cholesky flop count4.2e+04
    nnz(L+U), no partial pivoting, with AMD4,531
    nnz(V) for QR, upper bound nnz(L) for LU, with COLAMD2,768
    nnz(R) for QR, upper bound nnz(U) for LU, with COLAMD4,629

    SVD-based statistics:
    norm(A)2.23854e+08
    min(svd(A))80.0351
    cond(A)2.79695e+06
    rank(A)147
    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/lund_a 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.