psamm.lpsolver.cplex
– CPLEX LP solver¶
Linear programming solver using Cplex.

class
psamm.lpsolver.cplex.
Constraint
(prob, name)¶ Represents a constraint in a cplex.Problem

class
psamm.lpsolver.cplex.
CplexRangedProperty
(get_prop, doc=None)¶ Decorator for translating Cplex ranged properties.

class
psamm.lpsolver.cplex.
Problem
(**kwargs)¶ Represents an LPproblem of a cplex.Solver

add_linear_constraints
(*relations)¶ Add constraints to the problem
Each constraint is represented by a Relation, and the expression in that relation can be a set expression.

cplex
¶ The underlying Cplex object

define
(*names, **kwargs)¶ Define a variable in the problem.
Variables must be defined before they can be accessed by var() or set(). This function takes keyword arguments lower and upper to define the bounds of the variable (default: inf to inf). The keyword argument types can be used to select the type of the variable (Continuous (default), Binary or Integer). Setting any variables different than Continuous will turn the problem into an MILP problem. Raises ValueError if a name is already defined.

feasibility_tolerance
¶ Feasibility tolerance.

has_variable
(name)¶ Check whether variable is defined in the model.

integrality_tolerance
¶ Integrality tolerance.

optimality_tolerance
¶ Optimality tolerance.

set_linear_objective
(expression)¶ Set objective expression of the problem.

set_objective
(expression)¶ Set objective expression of the problem.

set_objective_sense
(sense)¶ Set type of problem (maximize or minimize)

solve_unchecked
(sense=None)¶ Solve problem and return result.
The user must manually check the status of the result to determine whether an optimal solution was found. A
SolverError
may still be raised if the underlying solver raises an exception.


class
psamm.lpsolver.cplex.
Result
(prob)¶ Represents the solution to a cplex.Problem
This object will be returned from the cplex.Problem.solve() method or by accessing the cplex.Problem.result property after solving a problem. This class should not be instantiated manually.
Result will evaluate to a boolean according to the success of the solution, so checking the truth value of the result will immediately indicate whether solving was successful.

get_value
(expression)¶ Return value of expression.

status
¶ Return string indicating the error encountered on failure

success
¶ Return boolean indicating whether a solution was found

unbounded
¶ Whether solution is unbounded
