Sage Reference Manual: Numerical Optimization - Mirrors

Sage Reference Manual: Numerical Optimization, Release 6.1.1
... p.add_constraint(b[u] + b[v], max=1)
sage: p.set_binary(b)
sage: p.solve(objective_only=True)
4.0
Constraints in the objective function are respected:
sage: p = MixedIntegerLinearProgram()
sage: x, y = p[0], p[1]
sage: p.add_constraint(2*x + 3*y, max = 6)
sage: p.add_constraint(3*x + 2*y, max = 6)
sage: p.set_objective(x + y + 7)
sage: p.set_integer(x); p.set_integer(y)
sage: p.solve()
9.0
solver_parameter(name, value=None)
Return or define a solver parameter
The solver parameters are by essence solver-specific, which means their meaning heavily depends on the
solver used.
(If you do not know which solver you are using, then you use use GLPK).
Aliases:
Very common parameters have aliases making them solver-independent. For example, the following:
sage: p = MixedIntegerLinearProgram(solver = "GLPK")
sage: p.solver_parameter("timelimit", 60)
Sets the solver to stop its computations after 60 seconds, and works with GLPK, CPLEX and Gurobi.
•"timelimit" – defines the maximum time spent on a computation. Measured in seconds.
Solver-specific parameters:
•GLPK : We have implemented very close to comprehensive coverage of the GLPK solver parameters
for the simplex and integer optimization methods. For details, see the documentation of
GLPKBackend.solver_parameter.
•CPLEX’s parameters are identified by a string. Their list is available on ILOG’s website.
The command
sage: p = MixedIntegerLinearProgram(solver = "CPLEX") # optional - CPLEX
sage: p.solver_parameter("CPX_PARAM_TILIM", 60) # optional - CPLEX
works as intended.
•Gurobi’s parameters should all be available through this method. Their list is available on Gurobi’s
website http://www.gurobi.com/documentation/5.5/reference-manual/node798.
INPUT:
•name (string) – the parameter
•value – the parameter’s value if it is to be defined, or None (default) to obtain its current value.
EXAMPLE:
2.2. Classes and methods 29