Matrix: HB/shl_400

Description: UNSYMMETRIC BASIS FROM LP PROBLEM SHELL

HB/shl_400 graph HB/shl_400 graph
(bipartite graph drawing) (graph drawing of A+A')

HB/shl_400 dmperm of HB/shl_400
scc of HB/shl_400

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  • Matrix group: HB
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  • download as a MATLAB mat-file, file size: 5 KB. Use UFget(249) or UFget('HB/shl_400') in MATLAB.
  • download in Matrix Market format, file size: 7 KB.
  • download in Rutherford/Boeing format, file size: 6 KB.

    Matrix properties
    number of rows663
    number of columns663
    nonzeros1,712
    structural full rank?yes
    structural rank663
    # of blocks from dmperm663
    # strongly connected comp.2
    explicit zero entries0
    nonzero pattern symmetry 0%
    numeric value symmetry 0%
    typeinteger
    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/shl_0

    Ordering statistics:result
    nnz(chol(P*(A+A'+s*I)*P')) with AMD15,169
    Cholesky flop count1.1e+06
    nnz(L+U), no partial pivoting, with AMD29,675
    nnz(V) for QR, upper bound nnz(L) for LU, with COLAMD24,791
    nnz(R) for QR, upper bound nnz(U) for LU, with COLAMD115,366

    SVD-based statistics:
    norm(A)9251.25
    min(svd(A))1.07604e-05
    cond(A)8.59754e+08
    rank(A)663
    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/shl_400 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.