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 81 - 100 of 138 in total
Id Name Group Rows Cols Nonzeros Kind Date Download File
621 lp_etamacro LPnetlib 400 816 2,537 Linear Programming Problem MATLAB Rutherford Boeing Matrix Market
704 lpi_bgetam LPnetlib 400 816 2,537 Linear Programming Problem 1993 MATLAB Rutherford Boeing Matrix Market
677 lp_scsd8 LPnetlib 397 2,750 8,584 Linear Programming Problem 1981 MATLAB Rutherford Boeing Matrix Market
673 lp_scorpion LPnetlib 388 466 1,534 Linear Programming Problem 1981 MATLAB Rutherford Boeing Matrix Market
693 lp_standgub LPnetlib 361 1,383 3,338 Linear Programming Problem 1989 MATLAB Rutherford Boeing Matrix Market
725 lpi_pang LPnetlib 361 741 2,933 Linear Programming Problem 1993 MATLAB Rutherford Boeing Matrix Market
692 lp_standata LPnetlib 359 1,274 3,230 Linear Programming Problem MATLAB Rutherford Boeing Matrix Market
691 lp_stair LPnetlib 356 614 4,003 Linear Programming Problem MATLAB Rutherford Boeing Matrix Market
703 lpi_bgdbg1 LPnetlib 348 629 1,662 Linear Programming Problem 1993 MATLAB Rutherford Boeing Matrix Market
699 lp_tuff LPnetlib 333 628 4,561 Linear Programming Problem 1989 MATLAB Rutherford Boeing Matrix Market
670 lp_scfxm1 LPnetlib 330 600 2,732 Linear Programming Problem 1981 MATLAB Rutherford Boeing Matrix Market
727 lpi_qual LPnetlib 323 464 1,646 Linear Programming Problem 1993 MATLAB Rutherford Boeing Matrix Market
729 lpi_refinery LPnetlib 323 464 1,626 Linear Programming Problem 1993 MATLAB Rutherford Boeing Matrix Market
730 lpi_vol1 LPnetlib 323 464 1,646 Linear Programming Problem 1993 MATLAB Rutherford Boeing Matrix Market
728 lpi_reactor LPnetlib 318 808 2,591 Linear Programming Problem 1993 MATLAB Rutherford Boeing Matrix Market
724 lpi_mondou2 LPnetlib 312 604 1,208 Linear Programming Problem MATLAB Rutherford Boeing Matrix Market
601 lp_bandm LPnetlib 305 472 2,494 Linear Programming Problem MATLAB Rutherford Boeing Matrix Market
632 lp_grow15 LPnetlib 300 645 5,620 Linear Programming Problem 1983 MATLAB Rutherford Boeing Matrix Market
678 lp_sctap1 LPnetlib 300 660 1,872 Linear Programming Problem 1981 MATLAB Rutherford Boeing Matrix Market
709 lpi_chemcom LPnetlib 288 744 1,590 Linear Programming Problem 1993 MATLAB Rutherford Boeing Matrix Market