Matrix: LPnetlib/lpi_ex73a

Description: Netlib LP problem ex73a: minimize c'*x, where Ax=b, lo<=x<=hi

LPnetlib/lpi_ex73a graph
(bipartite graph drawing)


LPnetlib/lpi_ex73a

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    Matrix properties
    number of rows193
    number of columns211
    nonzeros457
    structural full rank?yes
    structural rank193
    # of blocks from dmperm1
    # strongly connected comp.1
    explicit zero entries0
    nonzero pattern symmetry 0%
    numeric value symmetry 0%
    typeinteger
    structurerectangular
    Cholesky candidate?no
    positive definite?no

    authorZ. You
    editorJ. Chinneck
    date1992
    kindlinear programming problem
    2D/3D problem?no

    Additional fieldssize and type
    bfull 193-by-1
    cfull 211-by-1
    lofull 211-by-1
    hifull 211-by-1
    z0full 1-by-1

    Notes:

    An infeasible Netlib LP problem, in lp/infeas.  For more information        
    send email to netlib@ornl.gov 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                         
    ex73a       194    211      668   B            all cols are LO bounded      
                                                                                
    REFERENCES                                                                  
    ----------                                                                  
                                                                                
    J.W.  Chinneck (1992).  "Viability Analysis:  A Formulation Aid for All     
    Classes of Network Models", Naval Research Logistics, Vol.  39, pp.         
    531-543.                                                                    
                                                                                
    Added to Netlib on Sept. 19, 1993                                           
                                                                                
    

    Ordering statistics:result
    nnz(V) for QR, upper bound nnz(L) for LU, with COLAMD702
    nnz(R) for QR, upper bound nnz(U) for LU, with COLAMD785

    SVD-based statistics:
    norm(A)2.92875
    min(svd(A))6.14451e-17
    cond(A)4.76645e+16
    rank(A)188
    sprank(A)-rank(A)5
    null space dimension5
    full numerical rank?no
    singular value gap6.10231e+13

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

    LPnetlib/lpi_ex73a 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.