Matrix: HB/lns_3937

Description: UNSYMMETRIC MATRIX FROM I.P.J. DEC 1982. LINEARIZED N-S. COMPRESSIBLE

HB/lns_3937 graph HB/lns_3937 graph
(bipartite graph drawing) (graph drawing of A+A')


HB/lns_3937 dmperm of HB/lns_3937
scc of HB/lns_3937

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  • Matrix group: HB
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  • download as a MATLAB mat-file, file size: 135 KB. Use UFget(189) or UFget('HB/lns_3937') in MATLAB.
  • download in Matrix Market format, file size: 160 KB.
  • download in Rutherford/Boeing format, file size: 138 KB.

    Matrix properties
    number of rows3,937
    number of columns3,937
    nonzeros25,407
    structural full rank?yes
    structural rank3,937
    # of blocks from dmperm351
    # strongly connected comp.290
    explicit zero entries0
    nonzero pattern symmetry 85%
    numeric value symmetry 0%
    typereal
    structureunsymmetric
    Cholesky candidate?no
    positive definite?no

    authorI. Jones
    editorI. Duff, R. Grimes, J. Lewis
    date1982
    kindcomputational fluid dynamics problem
    2D/3D problem?yes

    Ordering statistics:result
    nnz(chol(P*(A+A'+s*I)*P')) with AMD106,263
    Cholesky flop count7.4e+06
    nnz(L+U), no partial pivoting, with AMD208,589
    nnz(V) for QR, upper bound nnz(L) for LU, with COLAMD184,022
    nnz(R) for QR, upper bound nnz(U) for LU, with COLAMD383,950

    SVD-based statistics:
    norm(A)3.26618e+11
    min(svd(A))1.63413e-05
    cond(A)1.99873e+16
    rank(A)2,895
    sprank(A)-rank(A)1,042
    null space dimension1,042
    full numerical rank?no
    singular value gap1.02543

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

    HB/lns_3937 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.