Matrix: JGD_BIBD/bibd_81_2

Description: Balanced Incomplete Block Design from Mark Giesbrecht, Univ. of Waterloo

JGD_BIBD/bibd_81_2 graph
(undirected graph drawing)

JGD_BIBD/bibd_81_2 dmperm of JGD_BIBD/bibd_81_2

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  • download as a MATLAB mat-file, file size: 10 KB. Use UFget(1939) or UFget('JGD_BIBD/bibd_81_2') in MATLAB.
  • download in Matrix Market format, file size: 13 KB.
  • download in Rutherford/Boeing format, file size: 8 KB.

    Matrix properties
    number of rows3,240
    number of columns3,240
    structural full rank?yes
    structural rank3,240
    # of blocks from dmperm3,240
    # strongly connected comp.3,240
    explicit zero entries0
    nonzero pattern symmetrysymmetric
    numeric value symmetrysymmetric
    Cholesky candidate?yes
    positive definite?yes

    authorM. Giesbrecht
    editorJ.-G. Dumas
    kindcombinatorial problem
    2D/3D problem?no


    Balanced Incomplete Block Design from Mark Giesbrecht, Univ. of Waterloo
    From Jean-Guillaume Dumas' Sparse Integer Matrix Collection,                      
    Filename in JGD collection: BIBD/bibd_81_2_3240x3240.sms                

    Ordering statistics:result
    nnz(chol(P*(A+A'+s*I)*P')) with AMD3,240
    Cholesky flop count3.2e+03
    nnz(L+U), no partial pivoting, with AMD3,240
    nnz(V) for QR, upper bound nnz(L) for LU, with COLAMD3,240
    nnz(R) for QR, upper bound nnz(U) for LU, with COLAMD3,240

    SVD-based statistics:
    null space dimension0
    full numerical rank?yes

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

    JGD_BIBD/bibd_81_2 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.