• SJSU Singular Matrix Database
  • Matrix group: HB
  • Click here for a description of the HB group.
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  • Matrix: HB/lns_3937
  • Description: UNSYMMETRIC MATRIX FROM I.P.J. DEC 1982. LINEARIZED N-S. COMPRESSIBLE
  • download as a MATLAB mat-file, file size: 161 KB. Use SJget(140) or SJget('HB/lns_3937') in MATLAB.
  • download in Matrix Market format, file size: 163 KB.
  • download in Rutherford/Boeing format, file size: 139 KB.

    HB/lns_3937

    Routine svd from Matlab 7.6.0.324 (R2008a) used to calculate the singular values.

    HB/lns_3937

    dmperm of HB/lns_3937

    scc of HB/lns_3937

    Matrix properties (click for a legend)  
    number of rows3,937
    number of columns3,937
    structural full rank?yes
    structural rank3,937
    numerical rank 2,895
    dimension of the numerical null space1,042
    numerical rank / min(size(A))0.73533
    Euclidean norm of A 3.2662e+011
    calculated singular value # 28950.24084
    numerical rank defined using a tolerance
    max(size(A))*eps(norm(A)) =
    0.2403
    calculated singular value # 28960.23487
    gap in the singular values at the numerical rank:
    singular value # 2895 / singular value # 2896
    1.0254
    calculated condition number1.999e+016
    condest1.0431e+017
    nonzeros25,407
    # of blocks from dmperm351
    # strongly connected comp.290
    entries not in dmperm blocks1,055
    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
    SJid140
    UFid189

    Ordering statistics:AMD METIS DMPERM+
    nnz(chol(P*(A+A'+s*I)*P'))106,263 109,465 229,694
    Cholesky flop count7.4e+006 7.3e+006 2.5e+007
    nnz(L+U), no partial pivoting208,589 214,993 456,506
    nnz(V) for QR, upper bound nnz(L) for LU184,022 207,476 188,233
    nnz(R) for QR, upper bound nnz(U) for LU383,950 441,158 379,354

    Maintained by Leslie Foster, last updated 24-Apr-2009.

    Entries 5 through 14 in the table of matrix properties and the singular
    value plot were created using SJsingular code. The other plots
    and statistics are produced using utilities from the SuiteSparse package.
    Matrix color plot pictures by cspy, a MATLAB function in the CSparse package.