Matrix: HB/str_600

Description: UNSYMMETRIC BASIS FROM LP PROBLEM STAIR

HB/str_600 graph HB/str_600 graph
(bipartite graph drawing) (graph drawing of A+A')

HB/str_600 dmperm of HB/str_600
scc of HB/str_600

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  • Matrix group: HB
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  • download as a MATLAB mat-file, file size: 19 KB. Use UFget(257) or UFget('HB/str_600') in MATLAB.
  • download in Matrix Market format, file size: 17 KB.
  • download in Rutherford/Boeing format, file size: 14 KB.

    Matrix properties
    number of rows363
    number of columns363
    nonzeros3,279
    structural full rank?yes
    structural rank363
    # of blocks from dmperm142
    # strongly connected comp.2
    explicit zero entries0
    nonzero pattern symmetry 2%
    numeric value symmetry 0%
    typereal
    structureunsymmetric
    Cholesky candidate?no
    positive definite?no

    authorM. Saunders
    editorA. Curtis, I. Duff, J. Reid
    date1978
    kindsubsequent optimization problem
    2D/3D problem?no

    Notes:

    next: - first: HB/str_0

    Ordering statistics:result
    nnz(chol(P*(A+A'+s*I)*P')) with AMD18,149
    Cholesky flop count1.7e+06
    nnz(L+U), no partial pivoting, with AMD35,935
    nnz(V) for QR, upper bound nnz(L) for LU, with COLAMD2,831
    nnz(R) for QR, upper bound nnz(U) for LU, with COLAMD8,017

    SVD-based statistics:
    norm(A)14.601
    min(svd(A))7.67684e-05
    cond(A)190195
    rank(A)363
    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/str_600 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.