Matrix: Pereyra/landmark

Description: Matrix from Victor Pereyra, Stanford University

Pereyra/landmark graph
(bipartite graph drawing)

Pereyra/landmark dmperm of Pereyra/landmark
scc of Pereyra/landmark

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  • Matrix group: Pereyra
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  • download as a MATLAB mat-file, file size: 6 MB. Use UFget(903) or UFget('Pereyra/landmark') in MATLAB.
  • download in Matrix Market format, file size: 14 MB.
  • download in Rutherford/Boeing format, file size: 12 MB.

    Matrix properties
    number of rows71,952
    number of columns2,704
    structural full rank?no
    structural rank2,673
    # of blocks from dmperm5
    # strongly connected comp.32
    explicit zero entries4,384
    nonzero pattern symmetry 0%
    numeric value symmetry 0%
    Cholesky candidate?no
    positive definite?no

    authorV. Pereyra
    editorT. Davis
    kindleast squares problem
    2D/3D problem?no

    Ordering statistics:result
    nnz(V) for QR, upper bound nnz(L) for LU, with COLAMD119,169,475
    nnz(R) for QR, upper bound nnz(U) for LU, with COLAMD1,544,068

    Note that all matrix statistics (except nonzero pattern symmetry) exclude the 4384 explicit zero entries.

    SVD-based statistics:
    null space dimension33
    full numerical rank?no
    singular value gap1634.09

    singular values (MAT file):click here
    SVD method used:s = svd (full (R)) ; where [~,R,E] = spqr (A) with droptol of zero

    Pereyra/landmark 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.