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


  • Matrix: HB/bcsstk31
  • Description: STIFFNESS MATRIX FOR AUTOMOBILE COMPONENT (MSC NASTRAN) - PATTERN ONLY
  • download as a MATLAB mat-file, file size: 620 KB. Use SJget(516) or SJget('HB/bcsstk31') in MATLAB.
  • download in Matrix Market format, file size: 1 MB.
  • download in Rutherford/Boeing format, file size: 557 KB.

    HB/bcsstk31

    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 7.6.0.324 (R2008a) to calculate the 6 largest singular values and associated error bounds.
    Routine spnrank, version 1.0, used with Matlab 7.6.0.324 (R2008a) to calculate singular values 16801 to 16806 and associated error bounds.

    HB/bcsstk31

    dmperm of HB/bcsstk31

    Matrix properties (click for a legend)  
    number of rows35,588
    number of columns35,588
    structural full rank?yes
    structural rank35,588
    numerical rank 16,803
    dimension of the numerical null space18,785
    numerical rank / min(size(A))0.47215
    Euclidean norm of A 57.969
    calculated singular value # 168030.00016106
    numerical rank defined using a tolerance
    max(size(A))*eps(norm(A)) =
    2.5287e-010
    calculated singular value # 168049.4304e-013
    gap in the singular values at the numerical rank:
    singular value # 16803 / singular value # 16804
    1.7079e+008
    calculated condition number-2
    condestInf
    nonzeros1,181,416
    # of blocks from dmperm2
    # strongly connected comp.2
    entries not in dmperm blocks3
    explicit zero entries0
    nonzero pattern symmetrysymmetric
    numeric value symmetrysymmetric
    typebinary
    structuresymmetric
    Cholesky candidate?yes
    positive definite?no

    authorR. Cigel, R. Grimes, J. Lewis, E. Meyer
    editorI. Duff, R. Grimes, J. Lewis
    date1986
    kindstructural problem
    2D/3D problem?yes
    SJid516
    UFid53

    Ordering statistics:AMD METIS DMPERM+
    nnz(chol(P*(A+A'+s*I)*P'))5,568,754 4,415,334 4,388,194
    Cholesky flop count2.9e+009 1.2e+009 1.2e+009
    nnz(L+U), no partial pivoting11,101,920 8,795,080 8,740,803
    nnz(V) for QR, upper bound nnz(L) for LU12,371,674 8,425,288 8,276,238
    nnz(R) for QR, upper bound nnz(U) for LU24,526,717 16,646,088 16,430,548

    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.