Matrix: Luong/photogrammetry

Description: Photogrammetry problem, B. Luong, FOGALE nanotech, France

Luong/photogrammetry graph
(bipartite graph drawing)


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  • download as a MATLAB mat-file, file size: 84 KB. Use UFget(1895) or UFget('Luong/photogrammetry') in MATLAB.
  • download in Matrix Market format, file size: 155 KB.
  • download in Rutherford/Boeing format, file size: 138 KB.

    Matrix properties
    number of rows1,388
    number of columns390
    structural full rank?yes
    structural rank390
    # of blocks from dmperm1
    # strongly connected comp.1
    explicit zero entries0
    nonzero pattern symmetry 0%
    numeric value symmetry 0%
    Cholesky candidate?no
    positive definite?no

    authorB. Luong
    editorT. Davis
    kindcomputer graphics/vision problem
    2D/3D problem?yes

    Additional fieldssize and type
    bfull 1388-by-1


    Photogrammetry problem from Bruno Luong, FOGALE nanotech, France.     
    The problem of interest is:                                           
        [U S V]=svd(full(A),0);                                           
    The spectrum has two parts:                                           
    - the singular values s(1) to s(end-7) are 1.7486e-004 to 3.4655e-007 
    (ratio 504.57).                                                       
    - the singular values s(end-6) to s(end) is smaller than 2.9614e-012  
    (ratio > 5.9e7).                                                      
    So in this problem, the following are considered:                     
    K = span is the kernel of A, and                     
    L = span = orthogonal(K) is isomorph to Im(A).         

    Ordering statistics:result
    nnz(V) for QR, upper bound nnz(L) for LU, with COLAMD212,121
    nnz(R) for QR, upper bound nnz(U) for LU, with COLAMD33,931

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

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

    Luong/photogrammetry 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.