Matrix: LPnetlib/lpi_box1

Description: Netlib LP problem box1: minimize c'*x, where Ax=b, lo<=x<=hi

LPnetlib/lpi_box1 graph
(bipartite graph drawing)


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  • Matrix group: LPnetlib
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  • download as a MATLAB mat-file, file size: 3 KB. Use UFget(707) or UFget('LPnetlib/lpi_box1') in MATLAB.
  • download in Matrix Market format, file size: 3 KB.
  • download in Rutherford/Boeing format, file size: 3 KB.

    Matrix properties
    number of rows231
    number of columns261
    structural full rank?yes
    structural rank231
    # 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

    authorZ. You
    editorJ. Chinneck
    kindlinear programming problem
    2D/3D problem?no

    Additional fieldssize and type
    bfull 231-by-1
    cfull 261-by-1
    lofull 261-by-1
    hifull 261-by-1
    z0full 1-by-1


    An infeasible Netlib LP problem, in lp/infeas.  For more information        
    send email to with the message:                             
    	send index from lp                                                         
    	send readme from lp/infeas                                                 
    The lp/infeas directory contains infeasible linear programming test problems
    collected by John W. Chinneck, Carleton Univ, Ontario Canada.  The following
    are relevant excerpts from lp/infeas/readme (by John W. Chinneck):          
    In the following, IIS stands for Irreducible Infeasible Subsystem, a set    
    of constraints which is itself infeasible, but becomes feasible when any    
    one member is removed.  Isolating an IIS from within the larger set of      
    constraints defining the model is one analysis approach.                    
    PROBLEM DESCRIPTION                                                         
    BOX1, EX72A, EX73A:  medium problems derived from research on using the     
    infeasibility version of viability analysis [Chinneck 1992] to analyze      
    petri net models.  All three problems are volatile, showing IISs of         
    widely differing size depending on the algorithm applied.  Contributor:     
    Zhengping You, Carleton University.                                         
    Name       Rows   Cols   Nonzeros Bounds      Notes                         
    box1        232    261      912   B            all cols are LO bounded      
    J.W.  Chinneck (1992).  "Viability Analysis:  A Formulation Aid for All     
    Classes of Network Models", Naval Research Logistics, Vol.  39, pp.         
    Added to Netlib on Sept. 19, 1993                                           

    Ordering statistics:result
    nnz(V) for QR, upper bound nnz(L) for LU, with COLAMD854
    nnz(R) for QR, upper bound nnz(U) for LU, with COLAMD1,164

    SVD-based statistics:
    null space dimension17
    full numerical rank?no
    singular value gap9.98733e+13

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

    LPnetlib/lpi_box1 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.