• SJSU Singular Matrix Database
  • Matrix group: HB
  • Click here for a description of the HB group.
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  • Matrix: HB/ash292
  • Description: SYMMETRIC PATTERN OF NORMAL MATRIX OF U.K. SURVEY. ASHKENAZI, 1974
  • download as a MATLAB mat-file, file size: 5 KB. Use SJget(52) or SJget('HB/ash292') in MATLAB.
  • download in Matrix Market format, file size: 3 KB.
  • download in Rutherford/Boeing format, file size: 3 KB.

    HB/ash292

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

    HB/ash292

    Matrix properties (click for a legend)  
    number of rows292
    number of columns292
    structural full rank?yes
    structural rank292
    numerical rank 289
    dimension of the numerical null space3
    numerical rank / min(size(A))0.98973
    Euclidean norm of A 9.1522
    calculated singular value # 2890.012413
    numerical rank defined using a tolerance
    max(size(A))*eps(norm(A)) =
    5.187e-013
    calculated singular value # 2901.0157e-015
    gap in the singular values at the numerical rank:
    singular value # 289 / singular value # 290
    1.2221e+013
    calculated condition number5.9047e+017
    condestInf
    nonzeros2,208
    # of blocks from dmperm1
    # strongly connected comp.1
    entries not in dmperm blocks0
    explicit zero entries0
    nonzero pattern symmetrysymmetric
    numeric value symmetrysymmetric
    typebinary
    structuresymmetric
    Cholesky candidate?yes
    positive definite?no

    authorV. Askenazi
    editorA. Curtis, I. Duff, J. Reid
    date1974
    kindleast squares problem
    2D/3D problem?no
    SJid52
    UFid8

    Ordering statistics:AMD METIS
    nnz(chol(P*(A+A'+s*I)*P'))2,496 2,888
    Cholesky flop count2.5e+004 3.6e+004
    nnz(L+U), no partial pivoting4,700 5,484
    nnz(V) for QR, upper bound nnz(L) for LU3,251 3,747
    nnz(R) for QR, upper bound nnz(U) for LU6,186 6,821

    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.