Matrix: LPnetlib/lp_blend

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

LPnetlib/lp_blend graph
(bipartite graph drawing)


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  • Matrix group: LPnetlib
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  • download as a MATLAB mat-file, file size: 4 KB. Use UFget(603) or UFget('LPnetlib/lp_blend') in MATLAB.
  • download in Matrix Market format, file size: 4 KB.
  • download in Rutherford/Boeing format, file size: 3 KB.

    Matrix properties
    number of rows74
    number of columns114
    structural full rank?yes
    structural rank74
    # 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

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

    Additional fieldssize and type
    bfull 74-by-1
    cfull 114-by-1
    lofull 114-by-1
    hifull 114-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 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           
    BLEND        75     83      521       3227       -3.0812149846E+01          
    Nick Gould supplied BLEND from the Harwell collection of LP test problems.  
    Concerning the problems he supplied, Nick Gould says that BLEND "is         
    a variant of the [oil refinery] problem in Murtagh's book (the              
    coefficients are different) which I understand John Reid obtained           
    from the people at NPL (Gill and Murray?); they were also the original      
    sources for the SC problems"                                                
    Added to Netlib on 6 April 1989                                             

    Ordering statistics:result
    nnz(V) for QR, upper bound nnz(L) for LU, with COLAMD1,842
    nnz(R) for QR, upper bound nnz(U) for LU, with COLAMD1,177

    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_blend 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.