Matrix: FEMLAB/problem1

Description: Comsol, Inc. www.femlab.com : small test problem

FEMLAB/problem1 graph
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FEMLAB/problem1

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  • Matrix group: FEMLAB
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  • download as a MATLAB mat-file, file size: 21 KB. Use UFget(929) or UFget('FEMLAB/problem1') in MATLAB.
  • download in Matrix Market format, file size: 28 KB.
  • download in Rutherford/Boeing format, file size: 27 KB.

    Matrix properties
    number of rows415
    number of columns415
    nonzeros2,779
    structural full rank?yes
    structural rank415
    # of blocks from dmperm1
    # strongly connected comp.1
    explicit zero entries0
    nonzero pattern symmetrysymmetric
    numeric value symmetry 65%
    typereal
    structureunsymmetric
    Cholesky candidate?no
    positive definite?no

    authorCOMSOL
    editorT. Davis
    date2003
    kind2D/3D problem
    2D/3D problem?yes

    Ordering statistics:result
    nnz(chol(P*(A+A'+s*I)*P')) with AMD4,539
    Cholesky flop count6.5e+04
    nnz(L+U), no partial pivoting, with AMD8,663
    nnz(V) for QR, upper bound nnz(L) for LU, with COLAMD6,699
    nnz(R) for QR, upper bound nnz(U) for LU, with COLAMD12,480

    SVD-based statistics:
    norm(A)6.47186
    min(svd(A))2.20559e-17
    cond(A)2.9343e+17
    rank(A)414
    sprank(A)-rank(A)1
    null space dimension1
    full numerical rank?no
    singular value gap1.03496e+15

    singular values (MAT file):click here
    SVD method used:s = svd (full (A)) ;
    status:ok

    FEMLAB/problem1 svd

    For a description of the statistics displayed above, click here.

    Maintained by Tim Davis, last updated 12-Mar-2014.
    Matrix pictures by cspy, a MATLAB function in the CSparse package.
    Matrix graphs by Yifan Hu, AT&T Labs Visualization Group.