PBOutput

cpbenchy run instances/ -s ortools -t 60 -p cpbenchy.observers:PBOutput

What it does

Writes what a solver in the Pseudo-Boolean competition prints, for each run on an OPB instance. The solution is a line with every variable as a literal:

o -7
o -9
s OPTIMUM FOUND
v x1 x2 -x3 x4

Each competition specifies what a solver prints:

• o lines with each better objective value, while it solves
• an s line with its answer: OPTIMUM FOUND, SATISFIABLE, UNSATISFIABLE or UNKNOWN
• v lines with the solution

The output goes to each run’s logs/<run_id>.pb.out, written inside the measured run, as a competition solver would print it, so it costs the run the time it would cost in the competition. A run that is killed keeps its o lines. Under cpbenchy solve, the output goes to stdout, where competitions read it.

Variables that occur in no constraint still get a value, from the number of variables in the instance’s header (* #variable= ...).

Use it

import cpbenchy
from cpbenchy import observers

cpbenchy.run("pb/", solvers=["exact", "ortools"], time_limit=60, plugins=[observers.PBOutput()])

cpbenchy run pb/ -s exact -s ortools -t 60 -p cpbenchy.observers:PBOutput

The PB rules enable it, with the competition’s limits.

What it records

Implementation

The PBOutput in src/cpbenchy/observers.py, lines 95–102 of 222, as of this version of the docs.

class PBOutput(CompetitionOutput):
    """Pseudo-Boolean competition output: every variable as `x1` or `-x1`."""

    name = "pb"
    formats = ("opb",)

    def solution(self, ctx):
        return [" ".join(fmt.literals(*numbered(ctx), prefix="x"))]