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 121 - 138 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
715 lpi_galenet LPnetlib 8 14 22 Linear Programming Problem MATLAB Rutherford Boeing Matrix Market
716 lpi_gosh LPnetlib 3,792 13,455 99,953 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
718 lpi_greenbea LPnetlib 2,393 5,596 31,074 Linear Programming Problem 1988 MATLAB Rutherford Boeing Matrix Market
719 lpi_itest2 LPnetlib 9 13 26 Linear Programming Problem 1991 MATLAB Rutherford Boeing Matrix Market
720 lpi_itest6 LPnetlib 11 17 29 Linear Programming Problem 1991 MATLAB Rutherford Boeing Matrix Market
721 lpi_klein1 LPnetlib 54 108 750 Linear Programming Problem MATLAB Rutherford Boeing Matrix Market
722 lpi_klein2 LPnetlib 477 531 5,062 Linear Programming Problem MATLAB Rutherford Boeing Matrix Market
723 lpi_klein3 LPnetlib 994 1,082 13,101 Linear Programming Problem MATLAB Rutherford Boeing Matrix Market
724 lpi_mondou2 LPnetlib 312 604 1,208 Linear Programming Problem MATLAB Rutherford Boeing Matrix Market
725 lpi_pang LPnetlib 361 741 2,933 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
727 lpi_qual 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
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
731 lpi_woodinfe LPnetlib 35 89 140 Linear Programming Problem 1989 MATLAB Rutherford Boeing Matrix Market