Matrix: NYPA/Maragal_2

Description: Rank deficient least squares problem, D. Maragal, NY Power Authority

NYPA/Maragal_2 graph
(bipartite graph drawing)


NYPA/Maragal_2 dmperm of NYPA/Maragal_2
scc of NYPA/Maragal_2

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  • download as a MATLAB mat-file, file size: 22 KB. Use UFget(1885) or UFget('NYPA/Maragal_2') in MATLAB.
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  • download in Rutherford/Boeing format, file size: 28 KB.

    Matrix properties
    number of rows555
    number of columns350
    nonzeros4,357
    structural full rank?no
    structural rank220
    # of blocks from dmperm13
    # strongly connected comp.110
    explicit zero entries0
    nonzero pattern symmetry 0%
    numeric value symmetry 0%
    typereal
    structurerectangular
    Cholesky candidate?no
    positive definite?no

    authorD. Maragal
    editorT. Davis
    date2008
    kindleast squares problem
    2D/3D problem?no

    Additional fieldssize and type
    bfull 555-by-1

    Notes:

    rank deficient (rank(A) < sprank(A) < size(A,2))
    rank: 171 sprank: 220 columns: 350              
    

    Ordering statistics:result
    nnz(V) for QR, upper bound nnz(L) for LU, with COLAMD30,077
    nnz(R) for QR, upper bound nnz(U) for LU, with COLAMD10,270

    SVD-based statistics:
    norm(A)10.2951
    min(svd(A))3.5996e-47
    cond(A)2.86006e+47
    rank(A)171
    sprank(A)-rank(A)49
    null space dimension179
    full numerical rank?no
    singular value gap1.18709e+13

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

    NYPA/Maragal_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.