Matrix: LPnetlib/lp_perold

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

LPnetlib/lp_perold graph
(bipartite graph drawing)

LPnetlib/lp_perold dmperm of LPnetlib/lp_perold

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  • Matrix group: LPnetlib
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  • download as a MATLAB mat-file, file size: 33 KB. Use UFget(653) or UFget('LPnetlib/lp_perold') in MATLAB.
  • download in Matrix Market format, file size: 34 KB.
  • download in Rutherford/Boeing format, file size: 25 KB.

    Matrix properties
    number of rows625
    number of columns1,506
    structural full rank?yes
    structural rank625
    # of blocks from dmperm3
    # strongly connected comp.1
    explicit zero entries0
    nonzero pattern symmetry 0%
    numeric value symmetry 0%
    Cholesky candidate?no
    positive definite?no

    authorN. Gould
    editorD. Gay
    kindlinear programming problem
    2D/3D problem?no

    Additional fieldssize and type
    bfull 625-by-1
    cfull 1506-by-1
    lofull 1506-by-1
    hifull 1506-by-1
    z0full 1-by-1


    A Netlib LP problem, in lp/data.  For more information                        
    send email to 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             
    PEROLD      626   1376     6026      47486  B    -9.3807580773E+03            
            BOUND-TYPE TABLE                                                      
    PEROLD     UP LO FX FR                                                        
    Nick Gould supplied PEROLD, from the Harwell collection of LP test problems.  
    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)                              
    PEROLD      -9.3807552782E+03    -9.3807553661E+03                            
    Concerning the problems he supplied, Nick Gould says that  PEROLD "is         
    another Pilot model (Pilot1)".                                                
    Added to Netlib on  6 April 1989                                              

    Ordering statistics:result
    nnz(V) for QR, upper bound nnz(L) for LU, with COLAMD135,137
    nnz(R) for QR, upper bound nnz(U) for LU, with COLAMD26,425

    SVD-based statistics:
    null space dimension0
    full numerical rank?yes

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

    LPnetlib/lp_perold 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.