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

  • Matrix: DNVS/trdheim
  • Description: Matrix Representation of TRDHEIM, Mesh of the Trondheim Fjord
  • download as a MATLAB mat-file, file size: 458 KB. Use SJget(405) or SJget('DNVS/trdheim') in MATLAB.
  • download in Matrix Market format, file size: 2 MB.
  • download in Rutherford/Boeing format, file size: 468 KB.


    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 2817 to 2822 and associated error bounds.


    Matrix properties (click for a legend)  
    number of rows22,098
    number of columns22,098
    structural full rank?yes
    structural rank22,098
    numerical rank 2,819
    dimension of the numerical null space19,279
    numerical rank / min(size(A))0.12757
    Euclidean norm of A 104.63
    calculated singular value # 28190.35282
    numerical rank defined using a tolerance
    max(size(A))*eps(norm(A)) =
    calculated singular value # 28205.154e-019
    gap in the singular values at the numerical rank:
    singular value # 2819 / singular value # 2820
    calculated condition number-2
    # of blocks from dmperm1
    # strongly connected comp.1
    entries not in dmperm blocks0
    explicit zero entries0
    nonzero pattern symmetrysymmetric
    numeric value symmetrysymmetric
    Cholesky candidate?yes
    positive definite?no

    authorC. Damhaug
    editorN. Gould, Y. Hu, J. Scott
    kindstructural problem
    2D/3D problem?yes

    Ordering statistics:AMD METIS
    nnz(chol(P*(A+A'+s*I)*P'))1,708,287 2,098,383
    Cholesky flop count1.6e+008 2.8e+008
    nnz(L+U), no partial pivoting3,394,476 4,174,668
    nnz(V) for QR, upper bound nnz(L) for LU7,074,375 3,557,271
    nnz(R) for QR, upper bound nnz(U) for LU21,764,103 8,898,495

    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.