Matrix: LPnetlib/lp_bnl1

Description: Netlib LP problem bnl1: minimize c'*x, where Ax=b, lo<=x<=hi

LPnetlib/lp_bnl1 graph
(bipartite graph drawing)


LPnetlib/lp_bnl1 dmperm of LPnetlib/lp_bnl1
scc of LPnetlib/lp_bnl1

  • Home page of the UF Sparse Matrix Collection
  • Matrix group: LPnetlib
  • Click here for a description of the LPnetlib group.
  • Click here for a list of all matrices
  • Click here for a list of all matrix groups
  • download as a MATLAB mat-file, file size: 20 KB. Use UFget(604) or UFget('LPnetlib/lp_bnl1') in MATLAB.
  • download in Matrix Market format, file size: 24 KB.
  • download in Rutherford/Boeing format, file size: 19 KB.

    Matrix properties
    number of rows643
    number of columns1,586
    nonzeros5,532
    structural full rank?no
    structural rank642
    # of blocks from dmperm12
    # strongly connected comp.12
    explicit zero entries0
    nonzero pattern symmetry 0%
    numeric value symmetry 0%
    typereal
    structurerectangular
    Cholesky candidate?no
    positive definite?no

    authorJ. Tomlin
    editorD. Gay
    date1989
    kindlinear programming problem
    2D/3D problem?no

    Additional fieldssize and type
    bfull 643-by-1
    cfull 1586-by-1
    lofull 1586-by-1
    hifull 1586-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 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         
    BNL1        644   1175     6129      42473        1.9776292856E+03        
                                                                              
    From John Tomlin.                                                         
                                                                              
    Bob Bixby reports that the CPLEX solver (running on a Sparc station)      
    finds slightly different optimal values for some of the problems.         
    On a MIPS processor, MINOS version 5.3 (with crash and scaling of         
    December 1989) also finds different optimal values for some of the        
    problems.  The following table shows the values that differ from those    
    shown above.  (Whether CPLEX finds different values on the recently       
    added problems remains to be seen.)                                       
                                                                              
    Problem        CPLEX(Sparc)          MINOS(MIPS)                          
    BNL1         1.9776295615E+03     1.9776293385E+03                        
                                                                              
    On the problems supplied by John Tomlin, MINOS 5.3 reports that about     
    10% to 57% of its steps are degenerate:                                   
         Name     Steps  Degen  Percent                                       
         BNL1      1614    169   10.47                                        
                                                                              
    Added to Netlib on 30 Oct. 1989                                           
                                                                              
    

    Ordering statistics:result
    nnz(V) for QR, upper bound nnz(L) for LU, with COLAMD95,006
    nnz(R) for QR, upper bound nnz(U) for LU, with COLAMD12,073

    SVD-based statistics:
    norm(A)170.484
    min(svd(A))1.21885e-60
    cond(A)1.39873e+62
    rank(A)642
    sprank(A)-rank(A)0
    null space dimension1
    full numerical rank?no
    singular value gap4.16852e+58

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

    LPnetlib/lp_bnl1 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.