• SJSU Singular Matrix Database
  • Matrix group: HB
  • Click here for a description of the HB group.
  • Click here for a list of all matrices
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  • Matrix: HB/lnsp_511
  • Description: UNSYMMETRIC MATRIX FROM I.P.J. DEC 1982. LINEARIZED N-S. COMPRESSIBLE
  • download as a MATLAB mat-file, file size: 20 KB. Use SJget(144) or SJget('HB/lnsp_511') in MATLAB.
  • download in Matrix Market format, file size: 17 KB.
  • download in Rutherford/Boeing format, file size: 15 KB.

    HB/lnsp_511

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

    HB/lnsp_511

    dmperm of HB/lnsp_511

    scc of HB/lnsp_511

    Matrix properties (click for a legend)  
    number of rows511
    number of columns511
    structural full rank?yes
    structural rank511
    numerical rank 469
    dimension of the numerical null space42
    numerical rank / min(size(A))0.91781
    Euclidean norm of A 4.2055e+010
    calculated singular value # 4690.0041691
    numerical rank defined using a tolerance
    max(size(A))*eps(norm(A)) =
    0.0038986
    calculated singular value # 4700.0035998
    gap in the singular values at the numerical rank:
    singular value # 469 / singular value # 470
    1.1582
    calculated condition number3.3292e+015
    condest5.1811e+015
    nonzeros2,796
    # of blocks from dmperm135
    # strongly connected comp.98
    entries not in dmperm blocks425
    explicit zero entries0
    nonzero pattern symmetry 80%
    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
    SJid144
    UFid193

    Ordering statistics:AMD METIS DMPERM+
    nnz(chol(P*(A+A'+s*I)*P'))5,840 6,399 10,386
    Cholesky flop count1.4e+005 1.7e+005 4.7e+005
    nnz(L+U), no partial pivoting11,169 12,287 20,686
    nnz(V) for QR, upper bound nnz(L) for LU9,623 11,031 8,861
    nnz(R) for QR, upper bound nnz(U) for LU20,208 23,083 17,018

    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.