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

  • Matrix: Oberwolfach/t2dah
  • Description: Oberwolfach: micropyros thruster
  • download as a MATLAB mat-file, file size: 1 MB. Use SJget(399) or SJget('Oberwolfach/t2dah') in MATLAB.
  • download in Matrix Market format, file size: 1 MB.
  • download in Rutherford/Boeing format, file size: 1 MB.


    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 (R2008a) to calculate the 6 largest singular values and associated error bounds.
    Routine spnrank, version 1.0, used with Matlab (R2008a) to calculate singular values 11442 to 11445 and associated error bounds.


    Matrix properties (click for a legend)  
    number of rows11,445
    number of columns11,445
    structural full rank?yes
    structural rank11,445
    numerical rank 11,444
    dimension of the numerical null space1
    numerical rank / min(size(A))0.99991
    Euclidean norm of A 266.27
    calculated singular value # 114441.6337e-007
    numerical rank defined using a tolerance
    max(size(A))*eps(norm(A)) =
    calculated singular value # 114451.9906e-014
    gap in the singular values at the numerical rank:
    singular value # 11444 / singular value # 11445
    calculated condition number1.3376e+016
    # of blocks from dmperm1
    # strongly connected comp.1
    entries not in dmperm blocks0
    explicit zero entries0
    nonzero pattern symmetrysymmetric
    numeric value symmetrysymmetric
    Cholesky candidate?no
    positive definite?no

    authorE. Rudnyi
    editorE. Rudnyi
    kindmodel reduction problem
    2D/3D problem?yes

    Additional fieldssize and type
    Esparse 11445-by-11445
    Bsparse 11445-by-1
    Csparse 7-by-11445
    cnamefull 7-by-7


    Primary matrix in this model reduction problem is the Oberwolfach A matrix

    Ordering statistics:AMD METIS
    nnz(chol(P*(A+A'+s*I)*P'))491,255 483,544
    Cholesky flop count4.1e+007 3.3e+007
    nnz(L+U), no partial pivoting971,065 955,643
    nnz(V) for QR, upper bound nnz(L) for LU841,710 826,206
    nnz(R) for QR, upper bound nnz(U) for LU2,001,083 1,879,892

    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.