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
714 lpi_forest6 LPnetlib 66 131 246 Linear Programming Problem 1993 MATLAB Rutherford Boeing Matrix Market
725 lpi_pang LPnetlib 361 741 2,933 Linear Programming Problem 1993 MATLAB Rutherford Boeing Matrix Market
716 lpi_gosh LPnetlib 3,792 13,455 99,953 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
703 lpi_bgdbg1 LPnetlib 348 629 1,662 Linear Programming Problem 1993 MATLAB Rutherford Boeing Matrix Market
704 lpi_bgetam LPnetlib 400 816 2,537 Linear Programming Problem 1993 MATLAB Rutherford Boeing Matrix Market
705 lpi_bgindy LPnetlib 2,671 10,880 66,266 Linear Programming Problem 1993 MATLAB Rutherford Boeing Matrix Market
706 lpi_bgprtr LPnetlib 20 40 70 Linear Programming Problem 1993 MATLAB Rutherford Boeing Matrix Market
726 lpi_pilot4i LPnetlib 410 1,123 5,264 Linear Programming Problem 1993 MATLAB Rutherford Boeing Matrix Market
709 lpi_chemcom LPnetlib 288 744 1,590 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
616 lp_d6cube LPnetlib 415 6,184 37,704 Linear Programming Problem 1993 MATLAB Rutherford Boeing Matrix Market
717 lpi_gran LPnetlib 2,658 2,525 20,111 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
644 lp_modszk1 LPnetlib 687 1,620 3,168 Linear Programming Problem 1994 MATLAB Rutherford Boeing Matrix Market
643 lp_maros_r7 LPnetlib 3,136 9,408 144,848 Linear Programming Problem 1994 MATLAB Rutherford Boeing Matrix Market
691 lp_stair LPnetlib 356 614 4,003 Linear Programming Problem MATLAB Rutherford Boeing Matrix Market
692 lp_standata LPnetlib 359 1,274 3,230 Linear Programming Problem MATLAB Rutherford Boeing Matrix Market
601 lp_bandm LPnetlib 305 472 2,494 Linear Programming Problem MATLAB Rutherford Boeing Matrix Market
597 lp_afiro LPnetlib 27 51 102 Linear Programming Problem MATLAB Rutherford Boeing Matrix Market