• SJSU Singular Matrix Database
  • Matrix group: HB
  • Click here for a description of the HB group.
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  • Matrix: HB/will199
  • Description: UNSYMMETRIC PATTERN OF ORDER 199 GIVEN BY WILLOUGHBY IN REID, 1970
  • download as a MATLAB mat-file, file size: 4 KB. Use SJget(225) or SJget('HB/will199') in MATLAB.
  • download in Matrix Market format, file size: 2 KB.
  • download in Rutherford/Boeing format, file size: 2 KB.

    HB/will199

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

    HB/will199

    dmperm of HB/will199

    Matrix properties (click for a legend)  
    number of rows199
    number of columns199
    structural full rank?yes
    structural rank199
    numerical rank 191
    dimension of the numerical null space8
    numerical rank / min(size(A))0.9598
    Euclidean norm of A 4.3881
    calculated singular value # 1910.029491
    numerical rank defined using a tolerance
    max(size(A))*eps(norm(A)) =
    1.7675e-013
    calculated singular value # 1927.0874e-016
    gap in the singular values at the numerical rank:
    singular value # 191 / singular value # 192
    4.161e+013
    calculated condition number1.9974e+018
    condestInf
    nonzeros701
    # of blocks from dmperm10
    # strongly connected comp.1
    entries not in dmperm blocks25
    explicit zero entries0
    nonzero pattern symmetry 6%
    numeric value symmetry 6%
    typebinary
    structureunsymmetric
    Cholesky candidate?no
    positive definite?no

    authorR. Willoughby
    editorI. Duff, R. Grimes, J. Lewis
    date1979
    kindstructural problem
    2D/3D problem?yes
    SJid225
    UFid273

    Ordering statistics:AMD METIS DMPERM+
    nnz(chol(P*(A+A'+s*I)*P'))4,595 5,039 1,590
    Cholesky flop count1.9e+005 2.2e+005 1.8e+004
    nnz(L+U), no partial pivoting8,991 9,879 3,006
    nnz(V) for QR, upper bound nnz(L) for LU1,230 1,225 1,085
    nnz(R) for QR, upper bound nnz(U) for LU2,403 2,453 2,181

    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.