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 101 - 120 of 138 in total
Id Name Group Rows Cols Nonzeros Kind Date Download File
608 lp_capri LPnetlib 271 482 1,896 Linear Programming Problem MATLAB Rutherford Boeing Matrix Market
601 lp_bandm LPnetlib 305 472 2,494 Linear Programming Problem MATLAB Rutherford Boeing Matrix Market
620 lp_e226 LPnetlib 223 472 2,768 Linear Programming Problem MATLAB Rutherford Boeing Matrix Market
673 lp_scorpion LPnetlib 388 466 1,534 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
730 lpi_vol1 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
711 lpi_cplex2 LPnetlib 224 378 1,215 Linear Programming Problem 1993 MATLAB Rutherford Boeing Matrix Market
641 lp_lotfi LPnetlib 153 366 1,136 Linear Programming Problem 1989 MATLAB Rutherford Boeing Matrix Market
700 lp_vtp_base LPnetlib 198 346 1,051 Linear Programming Problem MATLAB Rutherford Boeing Matrix Market
606 lp_bore3d LPnetlib 233 334 1,448 Linear Programming Problem MATLAB Rutherford Boeing Matrix Market
665 lp_sc205 LPnetlib 205 317 665 Linear Programming Problem MATLAB Rutherford Boeing Matrix Market
635 lp_israel LPnetlib 174 316 2,443 Linear Programming Problem MATLAB Rutherford Boeing Matrix Market
607 lp_brandy LPnetlib 220 303 2,202 Linear Programming Problem MATLAB Rutherford Boeing Matrix Market
634 lp_grow7 LPnetlib 140 301 2,612 Linear Programming Problem 1983 MATLAB Rutherford Boeing Matrix Market
602 lp_beaconfd LPnetlib 173 295 3,408 Linear Programming Problem MATLAB Rutherford Boeing Matrix Market
707 lpi_box1 LPnetlib 231 261 651 Linear Programming Problem 1992 MATLAB Rutherford Boeing Matrix Market
681 lp_share1b LPnetlib 117 253 1,179 Linear Programming Problem MATLAB Rutherford Boeing Matrix Market
712 lpi_ex72a LPnetlib 197 215 467 Linear Programming Problem 1992 MATLAB Rutherford Boeing Matrix Market
713 lpi_ex73a LPnetlib 193 211 457 Linear Programming Problem 1992 MATLAB Rutherford Boeing Matrix Market