• 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/t2dal
  • Description: Oberwolfach: micropyros thruster
  • download as a MATLAB mat-file, file size: 189 KB. Use SJget(221) or SJget('Oberwolfach/t2dal') in MATLAB.
  • download in Matrix Market format, file size: 194 KB.
  • download in Rutherford/Boeing format, file size: 177 KB.


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


    Matrix properties (click for a legend)  
    number of rows4,257
    number of columns4,257
    structural full rank?yes
    structural rank4,257
    numerical rank 4,256
    dimension of the numerical null space1
    numerical rank / min(size(A))0.99977
    Euclidean norm of A 145.64
    calculated singular value # 42563.6871e-007
    numerical rank defined using a tolerance
    max(size(A))*eps(norm(A)) =
    calculated singular value # 42577.2967e-015
    gap in the singular values at the numerical rank:
    singular value # 4256 / singular value # 4257
    calculated condition number1.996e+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 4257-by-4257
    Bsparse 4257-by-1
    Csparse 7-by-4257
    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'))115,326 111,958
    Cholesky flop count5.5e+006 4.7e+006
    nnz(L+U), no partial pivoting226,395 219,659
    nnz(V) for QR, upper bound nnz(L) for LU180,860 167,551
    nnz(R) for QR, upper bound nnz(U) for LU336,323 314,826

    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.