• SJSU Singular Matrix Database
  • Matrix group: HB
  • Click here for a description of the HB group.
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  • Matrix: HB/lnsp_131
  • Description: UNSYMMETRIC MATRIX FROM I.P.J. DEC 1982. LINEARIZED N-S. COMPRESSIBLE
  • download as a MATLAB mat-file, file size: 4 KB. Use SJget(143) or SJget('HB/lnsp_131') in MATLAB.
  • download in Matrix Market format, file size: 4 KB.
  • download in Rutherford/Boeing format, file size: 3 KB.

    HB/lnsp_131

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

    HB/lnsp_131

    dmperm of HB/lnsp_131

    scc of HB/lnsp_131

    Matrix properties (click for a legend)  
    number of rows131
    number of columns131
    structural full rank?yes
    structural rank131
    numerical rank 125
    dimension of the numerical null space6
    numerical rank / min(size(A))0.9542
    Euclidean norm of A 9.7721e+009
    calculated singular value # 1250.00037343
    numerical rank defined using a tolerance
    max(size(A))*eps(norm(A)) =
    0.00024986
    calculated singular value # 1260.00019092
    gap in the singular values at the numerical rank:
    singular value # 125 / singular value # 126
    1.9559
    calculated condition number1.2802e+015
    condest1.4903e+015
    nonzeros536
    # of blocks from dmperm65
    # strongly connected comp.48
    entries not in dmperm blocks175
    explicit zero entries0
    nonzero pattern symmetry 70%
    numeric value symmetry 2%
    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
    SJid143
    UFid192

    Ordering statistics:AMD METIS DMPERM+
    nnz(chol(P*(A+A'+s*I)*P'))560 623 595
    Cholesky flop count3.4e+003 4.8e+003 6.2e+003
    nnz(L+U), no partial pivoting989 1,115 1,234
    nnz(V) for QR, upper bound nnz(L) for LU809 838 546
    nnz(R) for QR, upper bound nnz(U) for LU1,728 1,889 1,083

    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.