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.



--------------------------------------------------------------------------------


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 21 - 40 of 138 in total
Id Name Group Rows Cols Nonzeros Kind Date Download File
638 lp_ken_11 LPnetlib 14,694 21,349 49,058 Linear Programming Problem 1991 MATLAB Rutherford Boeing Matrix Market
654 lp_pilot LPnetlib 1,441 4,860 44,375 Linear Programming Problem 1989 MATLAB Rutherford Boeing Matrix Market
660 lp_qap12 LPnetlib 3,192 8,856 38,304 Linear Programming Problem MATLAB Rutherford Boeing Matrix Market
616 lp_d6cube LPnetlib 415 6,184 37,704 Linear Programming Problem 1993 MATLAB Rutherford Boeing Matrix Market
702 lp_woodw LPnetlib 1,098 8,418 37,487 Linear Programming Problem MATLAB Rutherford Boeing Matrix Market
619 lp_dfl001 LPnetlib 6,071 12,230 35,632 Linear Programming Problem 1990 MATLAB Rutherford Boeing Matrix Market
615 lp_d2q06c LPnetlib 2,171 5,831 33,081 Linear Programming Problem 1989 MATLAB Rutherford Boeing Matrix Market
718 lpi_greenbea LPnetlib 2,393 5,596 31,074 Linear Programming Problem 1988 MATLAB Rutherford Boeing Matrix Market
631 lp_greenbeb LPnetlib 2,392 5,598 31,070 Linear Programming Problem 1984 MATLAB Rutherford Boeing Matrix Market
630 lp_greenbea LPnetlib 2,392 5,598 31,070 Linear Programming Problem 1984 MATLAB Rutherford Boeing Matrix Market
698 lp_truss LPnetlib 1,000 8,806 27,836 Linear Programming Problem 1990 MATLAB Rutherford Boeing Matrix Market
618 lp_degen3 LPnetlib 1,503 2,604 25,432 Linear Programming Problem 1989 MATLAB Rutherford Boeing Matrix Market
595 lp_80bau3b LPnetlib 2,262 12,061 23,264 Linear Programming Problem MATLAB Rutherford Boeing Matrix Market
613 lp_cycle LPnetlib 1,903 3,371 21,234 Linear Programming Problem 1989 MATLAB Rutherford Boeing Matrix Market
708 lpi_ceria3d LPnetlib 3,576 4,400 21,178 Linear Programming Problem MATLAB Rutherford Boeing Matrix Market
717 lpi_gran LPnetlib 2,658 2,525 20,111 Linear Programming Problem 1993 MATLAB Rutherford Boeing Matrix Market
609 lp_cre_a LPnetlib 3,516 7,248 18,168 Linear Programming Problem 1990 MATLAB Rutherford Boeing Matrix Market
649 lp_pds_02 LPnetlib 2,953 7,716 16,571 Linear Programming Problem 1990 MATLAB Rutherford Boeing Matrix Market
688 lp_ship12l LPnetlib 1,151 5,533 16,276 Linear Programming Problem MATLAB Rutherford Boeing Matrix Market
611 lp_cre_c LPnetlib 3,068 6,411 15,977 Linear Programming Problem 1990 MATLAB Rutherford Boeing Matrix Market