• SJSU Singular Matrix Database
  • Matrix group: Norris
  • Click here for a description of the Norris group.
  • Click here for a list of all matrices
  • Click here for a list of all matrix groups

  • Matrix: Norris/lung2
  • Description: S.Norris, Univ. Auckland. Coupled temp,water vapour transport in lung
  • download as a MATLAB mat-file, file size: 3 MB. Use SJget(431) or SJget('Norris/lung2') in MATLAB.
  • download in Matrix Market format, file size: 5 MB.
  • download in Rutherford/Boeing format, file size: 4 MB.


    A singular value of A is guaranteed1 to be in the interval pictured by the blue bars around each of the calculated singular values.

    Routine svds_err, version 1.0, used with Matlab (R2008a) to calculate the 6 largest singular values and associated error bounds.
    Routine spnrank, version 1.0, used with Matlab (R2008a) to calculate singular values 55101 to 55106 and associated error bounds.


    dmperm of Norris/lung2

    Matrix properties (click for a legend)  
    number of rows109,460
    number of columns109,460
    structural full rank?yes
    structural rank109,460
    numerical rank 55,103
    dimension of the numerical null space54,357
    numerical rank / min(size(A))0.50341
    Euclidean norm of A 516.92
    calculated singular value # 551031.2448e-008
    numerical rank defined using a tolerance
    max(size(A))*eps(norm(A)) =
    calculated singular value # 551041.2028e-008
    gap in the singular values at the numerical rank:
    singular value # 55103 / singular value # 55104
    calculated condition number-2
    # of blocks from dmperm2
    # strongly connected comp.2
    entries not in dmperm blocks164,188
    explicit zero entries0
    nonzero pattern symmetry 57%
    numeric value symmetry 0%
    Cholesky candidate?no
    positive definite?no

    authorS. Norris
    editorT. Davis
    kindcomputational fluid dynamics problem
    2D/3D problem?yes

    Ordering statistics:AMD METIS DMPERM+
    nnz(chol(P*(A+A'+s*I)*P'))383,106 452,802 218,918
    Cholesky flop count1.4e+006 2.1e+006 4.4e+005
    nnz(L+U), no partial pivoting656,752 796,144 492,564
    nnz(V) for QR, upper bound nnz(L) for LU346,634 375,170 218,918
    nnz(R) for QR, upper bound nnz(U) for LU701,118 710,896 525,620

    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.