compute_infeasibility_explanation

(function from pyomo.contrib.iis.mis)

pyomo.contrib.iis.mis.compute_infeasibility_explanation(model, solver, tee=False, tolerance=1e-08, logger=<Logger pyomo.contrib.iis (INFO)>)[source]

This function attempts to determine why a given model is infeasible. It deploys two main algorithms:

  1. Successfully relaxes the constraints of the problem, and reports to the user some sets of constraints and variable bounds, which when relaxed, creates a feasible model.

  2. Uses the information collected from (1) to attempt to compute a Minimal Infeasible System (MIS), which is a set of constraints and variable bounds which appear to be in conflict with each other. It is minimal in the sense that removing any single constraint or variable bound would result in a feasible subsystem.

Parameters:

  • model (BlockData) – A pyomo block

  • solver (OptSolver | SolverBase | str) – A pyomo solver object or a string for SolverFactory

  • tee (bool) – Display intermediate solves conducted

  • tolerance (float) – The feasibility tolerance to use when declaring a constraint feasible.

  • logger (logging.Logger) – A logger for messages. Uses pyomo.contrib.mis logger by default.