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


  • Matrix: Okunbor/aft01
  • Description: Acoustic Radiation around aft duct fan. D. Okunbor, Univ Missouri-Rolla
  • download as a MATLAB mat-file, file size: 971 KB. Use SJget(374) or SJget('Okunbor/aft01') in MATLAB.
  • download in Matrix Market format, file size: 458 KB.
  • download in Rutherford/Boeing format, file size: 374 KB.

    Okunbor/aft01

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

    Okunbor/aft01

    Matrix properties (click for a legend)  
    number of rows8,205
    number of columns8,205
    structural full rank?yes
    structural rank8,205
    numerical rank 1
    dimension of the numerical null space8,204
    numerical rank / min(size(A))0.00012188
    Euclidean norm of A 1e+015
    calculated singular value # 11e+015
    numerical rank defined using a tolerance
    max(size(A))*eps(norm(A)) =
    1025.6
    calculated singular value # 2833.8
    gap in the singular values at the numerical rank:
    singular value # 1 / singular value # 2
    1.1993e+012
    calculated condition number4.4691e+018
    condest9.3556e+018
    nonzeros125,567
    # of blocks from dmperm1
    # strongly connected comp.1
    entries not in dmperm blocks0
    explicit zero entries0
    nonzero pattern symmetrysymmetric
    numeric value symmetrysymmetric
    typereal
    structuresymmetric
    Cholesky candidate?yes
    positive definite?yes

    authorW. Eversman, D. Okunbor
    editorT. Davis
    date2001
    kindacoustics problem
    2D/3D problem?yes
    SJid374
    UFid791

    Ordering statistics:AMD METIS
    nnz(chol(P*(A+A'+s*I)*P'))289,180 324,352
    Cholesky flop count1.7e+007 2.0e+007
    nnz(L+U), no partial pivoting570,155 640,499
    nnz(V) for QR, upper bound nnz(L) for LU517,970 533,936
    nnz(R) for QR, upper bound nnz(U) for LU1,234,184 1,207,794

    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.