• 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/nnc1374
  • Description: U NATIONAL NUCLEAR CORP. FISSION REACTOR SIESMIC STUDIES
  • download as a MATLAB mat-file, file size: 25 KB. Use SJget(160) or SJget('HB/nnc1374') in MATLAB.
  • download in Matrix Market format, file size: 32 KB.
  • download in Rutherford/Boeing format, file size: 18 KB.

    HB/nnc1374

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

    HB/nnc1374

    dmperm of HB/nnc1374

    Matrix properties (click for a legend)  
    number of rows1,374
    number of columns1,374
    structural full rank?yes
    structural rank1,374
    numerical rank 1,308
    dimension of the numerical null space66
    numerical rank / min(size(A))0.95197
    Euclidean norm of A 1102.1
    calculated singular value # 13081.6025e-009
    numerical rank defined using a tolerance
    max(size(A))*eps(norm(A)) =
    3.1241e-010
    calculated singular value # 13092.8157e-010
    gap in the singular values at the numerical rank:
    singular value # 1308 / singular value # 1309
    5.6913
    calculated condition number3.719e+014
    condest4.1082e+015
    nonzeros8,588
    # of blocks from dmperm57
    # strongly connected comp.1
    entries not in dmperm blocks194
    explicit zero entries18
    nonzero pattern symmetry 82%
    numeric value symmetry 59%
    typereal
    structureunsymmetric
    Cholesky candidate?no
    positive definite?no

    authorNational Nuclear Corp.
    editorI. Duff, R. Grimes, J. Lewis
    date1982
    kind2D/3D problem
    2D/3D problem?yes
    SJid160
    UFid214

    Ordering statistics:AMD METIS DMPERM+
    nnz(chol(P*(A+A'+s*I)*P'))13,888 15,220 33,466
    Cholesky flop count2.2e+005 2.8e+005 1.3e+006
    nnz(L+U), no partial pivoting26,402 29,066 65,752
    nnz(V) for QR, upper bound nnz(L) for LU34,806 43,373 34,532
    nnz(R) for QR, upper bound nnz(U) for LU76,396 87,609 72,029

    Note that all matrix statistics (except nonzero pattern symmetry) exclude the 18 explicit zero entries.

    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.