Matrix: LPnetlib/lp_pds_20

Description: Netlib LP problem pds_20: minimize c'*x, where Ax=b, lo<=x<=hi

LPnetlib/lp_pds_20 graph
(bipartite graph drawing)

LPnetlib/lp_pds_20 dmperm of LPnetlib/lp_pds_20
scc of LPnetlib/lp_pds_20

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  • Matrix group: LPnetlib
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  • download as a MATLAB mat-file, file size: 553 KB. Use UFget(652) or UFget('LPnetlib/lp_pds_20') in MATLAB.
  • download in Matrix Market format, file size: 930 KB.
  • download in Rutherford/Boeing format, file size: 681 KB.

    Matrix properties
    number of rows33,874
    number of columns108,175
    structural full rank?no
    structural rank33,798
    # of blocks from dmperm853
    # strongly connected comp.77
    explicit zero entries0
    nonzero pattern symmetry 0%
    numeric value symmetry 0%
    Cholesky candidate?no
    positive definite?no

    authorJ. Kennington
    editorI. Lustig
    kindlinear programming problem
    2D/3D problem?no

    Additional fieldssize and type
    bfull 33874-by-1
    cfull 108175-by-1
    lofull 108175-by-1
    hifull 108175-by-1
    z0full 1-by-1


    A Netlib LP problem, in lp/data/kennington.  For more information             
    send email to with the message:                               
    	 send index from lp                                                          
    	 send readme from lp/data                                                    
    	 send readme from lp/data/kennington                                         
    The following are relevant excerpts from lp/data/kennington/readme:           
    The "Kennington" problems: sixteen problems described in "An Empirical        
    Evaluation of the KORBX Algorithms for Military Airlift Applications"         
    by W. J. Carolan, J. E. Hill, J. L. Kennington, S. Niemi, S. J.               
    Wichmann (Operations Research vol. 38, no. 2 (1990), pp. 240-248).            
    The following table gives some statistics for the "Kennington"                
    problems.  The number of columns excludes slacks and surpluses.               
    The bounds column tells how many entries appear in the BOUNDS                 
    section of the MPS file.  The mpc column shows the bytes in                   
    the problem after "uncompress" and before "emps"; MPS shows                   
    the bytes after "emps".  The optimal values were computed by                  
    Vanderbei's ALPO, running on an SGI computer (with binary IEEE                
    Name       rows  columns  nonzeros  bounds      mpc      MPS     optimal value
    PDS-20    33875  105728    304153    34888   2856653  11550890   2.3821659e+10
    Submitted to Netlib by Irv Lustig.                                            

    Ordering statistics:result
    nnz(V) for QR, upper bound nnz(L) for LU, with COLAMD189,770,628
    nnz(R) for QR, upper bound nnz(U) for LU, with COLAMD6,827,078

    SVD-based statistics:
    null space dimension87
    full numerical rank?no
    singular value gap8.44444e+13

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

    LPnetlib/lp_pds_20 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.