Group LPnetlib

Group Description
NETLIB Linear Programming problems, www.netlib.org.

matrices/LPnetlib/README.  Tim Davis, May 15, 1997. (davis :at the domain:
cise.ufl.edu)

The files in this directory are a translation of the linear programming
problems in Netlib.  You can obtain more information about the Netlib LP
problems by sending email to netlib :at the domain:
ornl.gov with the message
"send index from lp".


++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
NOTICE!  The Netlib LP problems, in MPS format, should be considered the
"canonical" problems.  If you find any problems with different optimal
objectives than what is reported in Netlib, then please let me know.
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

The Netlib LP problems are in MPS or compressed MPS format.  Any compressed
MPS files were uncompressed using emps.c in the Netlib lp/data directory.
The MPS files were then converted to the KAR format using the mpsrd program
by M.G.C. Resende and G. Veiga.  The mpsrd program does not process RANGES,
so five problems (boeing1, boeing2, forplan, nesm, and seba) do not appear
here.  The KAR format is written out by mpsrd as follows:

c     name   - problem name (same as mps name card)
      write(out,'(a8)') name
c     m      - number or rows (input)
c     n      - number of columns (input)
      write(out,*) m,n
c     ia     - pointers to the begining of storage of column
      write(out,*) (ia(i),i=1,n+1)
c     ja     - row indices for each non zero entry (input)
      write(out,*) (ja(i),i=1,ia(n+1)-1)
c     a      - non zero entries (input)
      write(out,*) (a(i),i=1,ia(n+1)-1)
c     b      - right hand side (input)
      write(out,*) (b(i),i=1,m)
c     c      - objective vector (minimize)
      write(out,*) (c(i),i=1,n)
c     z0     - initial fixed value for objective
      write(out,*) z0
c     lobnd  - lower bounds on variables
      write(out,*) (lobnd(i),i=1,n)
c     upbnd  - upper bounds on variables
      write(out,*) (upbnd(i),i=1,n)

Mpsrd converts the MPS problem into a single form:

	minimize c'*x, subject to Ax=b and l<=x<=u.
	(and given an initial value of the objective, z0).

Next, the KAR formatted version of the LP problem was converted into
two formats by the readkar.f program, written by Tim Davis.  It generates
a single Matlab script, such as lp_afiro.m for the AFIRO problem.
For infeasible (lp/infeas) problems, the prefix is lpi_ (lpi_galenet.m for
the problem GALENET, for example).  This prefix was chosen so that you
are sure to notice that the problem is infeasible, and also because there
are two versions of the same problem in Netlib (GREENBEA), one feasible
and the other not.



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The *.clu files contain the c, l, and u vectors,
and the scalar z0, for the LP problems held in
RRA format in the LPnetlib directory.  The dense vectors
appear in order: c, l, u, and then z0.  One entry is held
on each line. 

The RRA files contain A and b, in Harwell/Boeing format.

The LP problems are all of the form

	minimize c'*x, subject to Ax=b and l<=x<=u
	and where z0 is the initial value of the
	objective.
Displaying collection matrices 61 - 80 of 138 in total
Id Name Group Rows Cols Nonzeros Kind Date Download File
679 lp_sctap2 LPnetlib 1,090 2,500 7,334 Linear Programming Problem 1981 MATLAB Rutherford Boeing Matrix Market
662 lp_qap8 LPnetlib 912 1,632 7,296 Linear Programming Problem MATLAB Rutherford Boeing Matrix Market
687 lp_ship08s LPnetlib 778 2,467 7,194 Linear Programming Problem MATLAB Rutherford Boeing Matrix Market
628 lp_ganges LPnetlib 1,309 1,706 6,937 Linear Programming Problem MATLAB Rutherford Boeing Matrix Market
622 lp_fffff800 LPnetlib 524 1,028 6,401 Linear Programming Problem MATLAB Rutherford Boeing Matrix Market
684 lp_ship04l LPnetlib 402 2,166 6,380 Linear Programming Problem MATLAB Rutherford Boeing Matrix Market
653 lp_perold LPnetlib 625 1,506 6,148 Linear Programming Problem 1989 MATLAB Rutherford Boeing Matrix Market
632 lp_grow15 LPnetlib 300 645 5,620 Linear Programming Problem 1983 MATLAB Rutherford Boeing Matrix Market
604 lp_bnl1 LPnetlib 643 1,586 5,532 Linear Programming Problem 1989 MATLAB Rutherford Boeing Matrix Market
671 lp_scfxm2 LPnetlib 660 1,200 5,469 Linear Programming Problem 1981 MATLAB Rutherford Boeing Matrix Market
726 lpi_pilot4i LPnetlib 410 1,123 5,264 Linear Programming Problem 1993 MATLAB Rutherford Boeing Matrix Market
655 lp_pilot4 LPnetlib 410 1,123 5,264 Linear Programming Problem MATLAB Rutherford Boeing Matrix Market
722 lpi_klein2 LPnetlib 477 531 5,062 Linear Programming Problem MATLAB Rutherford Boeing Matrix Market
600 lp_agg3 LPnetlib 516 758 4,756 Linear Programming Problem 1988 MATLAB Rutherford Boeing Matrix Market
599 lp_agg2 LPnetlib 516 758 4,740 Linear Programming Problem 1988 MATLAB Rutherford Boeing Matrix Market
699 lp_tuff LPnetlib 333 628 4,561 Linear Programming Problem 1989 MATLAB Rutherford Boeing Matrix Market
685 lp_ship04s LPnetlib 402 1,506 4,400 Linear Programming Problem MATLAB Rutherford Boeing Matrix Market
676 lp_scsd6 LPnetlib 147 1,350 4,316 Linear Programming Problem 1981 MATLAB Rutherford Boeing Matrix Market
617 lp_degen2 LPnetlib 444 757 4,201 Linear Programming Problem 1989 MATLAB Rutherford Boeing Matrix Market
691 lp_stair LPnetlib 356 614 4,003 Linear Programming Problem MATLAB Rutherford Boeing Matrix Market