Matrix: LPnetlib/lp_modszk1

Description: Netlib LP problem modszk1: minimize c'*x, where Ax=b, lo<=x<=hi

LPnetlib/lp_modszk1 graph
(bipartite graph drawing)


LPnetlib/lp_modszk1 dmperm of LPnetlib/lp_modszk1
scc of LPnetlib/lp_modszk1

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  • download as a MATLAB mat-file, file size: 19 KB. Use UFget(644) or UFget('LPnetlib/lp_modszk1') in MATLAB.
  • download in Matrix Market format, file size: 18 KB.
  • download in Rutherford/Boeing format, file size: 18 KB.

    Matrix properties
    number of rows687
    number of columns1,620
    nonzeros3,168
    structural full rank?no
    structural rank686
    # of blocks from dmperm3
    # strongly connected comp.3
    explicit zero entries0
    nonzero pattern symmetry 0%
    numeric value symmetry 0%
    typereal
    structurerectangular
    Cholesky candidate?no
    positive definite?no

    authorI. Maros
    editorD. Gay
    date1994
    kindlinear programming problem
    2D/3D problem?no

    Additional fieldssize and type
    bfull 687-by-1
    cfull 1620-by-1
    lofull 1620-by-1
    hifull 1620-by-1
    z0full 1-by-1

    Notes:

    A Netlib LP problem, in lp/data.  For more information                    
    send email to netlib@ornl.gov with the message:                           
                                                                              
    	 send index from lp                                                      
    	 send readme from lp/data                                                
                                                                              
    The following are relevant excerpts from lp/data/readme (by David M. Gay):
                                                                              
    The column and nonzero counts in the PROBLEM SUMMARY TABLE below exclude  
    slack and surplus columns and the right-hand side vector, but include     
    the cost row.  We have omitted other free rows and all but the first      
    right-hand side vector, as noted below.  The byte count is for the        
    MPS compressed file; it includes a newline character at the end of each   
    line.  These files start with a blank initial line intended to prevent    
    mail programs from discarding any of the data.  The BR column indicates   
    whether a problem has bounds or ranges:  B stands for "has bounds", R     
    for "has ranges".  The BOUND-TYPE TABLE below shows the bound types       
    present in those problems that have bounds.                               
                                                                              
    The optimal value is from MINOS version 5.3 (of Sept. 1988)               
    running on a VAX with default options.                                    
                                                                              
                           PROBLEM SUMMARY TABLE                              
                                                                              
    Name       Rows   Cols   Nonzeros    Bytes  BR      Optimal Value         
    MODSZK1     688   1620     4158      40908  B     3.2061972906E+02        
                                                                              
            BOUND-TYPE TABLE                                                  
    MODSZK1             FR                                                    
                                                                              
    From Istvan Maros.                                                        
    Concerning the problems he submitted, Istvan Maros says that              
    MODSZK1 is a "real-life problem" that                                     
    is "very degenerate" and on which a dual simplex algorithm "may require   
    up to 10 times" fewer iterations than a primal simplex algorithm.  It     
    "is a multi-sector economic planning model (a kind of an input/output     
    model in economy)" and "is an old problem of mine and it is not easy to   
    recall more."                                                             
                                                                              
    Added to Netlib on  17 Jan. 1994                                          
                                                                              
    

    Ordering statistics:result
    nnz(V) for QR, upper bound nnz(L) for LU, with COLAMD71,390
    nnz(R) for QR, upper bound nnz(U) for LU, with COLAMD12,434

    SVD-based statistics:
    norm(A)4.87556
    min(svd(A))9.11989e-20
    cond(A)5.34607e+19
    rank(A)686
    sprank(A)-rank(A)0
    null space dimension1
    full numerical rank?no
    singular value gap1.32806e+18

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

    LPnetlib/lp_modszk1 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.