Benchmarks that may be used in the evaluation
This page lets you download a preliminary set of benchmarks
that may be used during the evaluation. These are mostly last year's
benchmarks which have been translated to the new syntax (all variables
renamed to 'x' followed by an integer, no more '*',...). Besides
variables which do not appear in a constraint have been removed.
Each benchmark that was initially named file has
been normalized and renamed to normalized-opb-file. Comments in the original
files were preserved as much as possible. Comments indicating the
number of variables and constraints, as well as the initial file name
and the variables renaming have been prepended.
We insist on the fact that these files
are only a preliminary set of benchmarks that is only made available so
that you can test your solvers. Some benchmarks will be removed from
the
evalution because they are too easy, or duplicates of another
benchmark, or incorrectly translated, etc... Besides, the evaluation
will use other benchmarks which are not yet available.
These benchmarks come from different sources
- Submitted benchmarks
These are the instances which were directly submitted to last year's
evaluation
- Benchmarks obtained on the web
The comments in the
normalized file (as well as the path to the file) should give you a
good indication on where it comes
from.
- Benchmarks translated from MPS files gathered on the web
These benchmarks are a translation of linear programming problems
available on the web and expressed in MPS format. These benchmarks are
named normalized-mps-vX-YY-ZZ-file where X is the version of the translator,
YY is the maximum number
of
bits used for the representation of the integer part of a variable, ZZ is the number of bits used for
the representation of the fractional part of a variable and file is the name of the initial MPS
file. Note that the translation process hasn't been thoroughly tested.
Therefore, the semantics of these files might be different from the
initial MPS file. Furthermore, the limitation on the number of
bits used to represent a real variable imposes constraints which
are not initially expressed in the MPS file. Therefore, the set of
solutions is likely to be different. At last, the translation process
tends to generate huge coefficients that can exceed the limits of a 32
bits integer.
For each instance file that doesn't use only small integers, a new
instance will be generated with reduced coefficients. These instances
are named normalized-reduced-file.
Reduced coefficients are obtained by dividing all numbers in a
constraint by a same number so that the resulting constraint fits in
category SMALLINT. This ensures that we will have more instances in the
SMALLINT category than in any other ones. Keep in mind however that a
reduced constraint is not equivalent to the initial one. Therefore
normalized-reduced-file does
not have the same semantics as file.
Availables instances are grouped by category.