CODEWITHSUNDEEP
pythonlinear-programmingcplexpulp
Miguel
Miguel

Reputation: 433

PULP - How to get the CPLEX solver status instead of the LpStatus stauts?

I'm using the CPLEX solver via PULP in Python. When I solve a problem with time limit, CPLEX prints to the screen the code 107 which means "Time limit exceeded, but integer solution exists". However, if I print the status of pulp.LpStatus[problem.status] what I get back is the value 1 which according to pulp's documentation means an optimal solution has been found, which is actually wrong.

How can I access the CPLEX status codes instead of PULP's?

Upvotes: 2

Views: 1553

Answers (1)

abc
abc

Reputation: 11939

You can directly access CPLEX status code and status string. Consider the following example:

>>> import pulp 
>>> prob = pulp.LpProblem("example", pulp.LpMinimize)
>>> x = pulp.LpVariable('x', lowBound=0, upBound=1)
>>> prob+= x <= -1

  • Example 1 - Time limit exceeded

    >>> solver = pulp.CPLEX_PY(msg=0, timeLimit=0)
>>> prob.setSolver(solver)
>>> prob.solve()
-3
>>> solver.solverModel.solution.get_status()
108
>>> solver.solverModel.solution.get_status_string()
'time limit exceeded, no integer solution'

  • Example 2 - Infeasible

    >>> solver = pulp.CPLEX_PY(msg=0)
>>> prob.setSolver(solver)
>>> prob.solve()
-1
>>> solver.solverModel.solution.get_status()
103
>>> solver.solverModel.solution.get_status_string()
'integer infeasible'

Upvotes: 2

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