Model.computeIIS()


Model.computeIIS()

computeIIS ( void )

Compute an Irreducible Inconsistent Subsystem (IIS). An IIS is a subset of the constraints and variable bounds of the original model. If all constraints in the model except those in the IIS are removed, the model is still infeasible. However, further removing any one member of the IIS produces a feasible result.

This method populates the IISCONSTR and IISQCONSTR constraint attributes, the IISSOS SOS attribute, and the IISLB, and IISUB variable attributes. You can also obtain information about the results of the IIS computation by writing an .ilp format file (see Model.write). This file contains only the IIS from the original model.

Note that this method can be used to compute IISs for both continuous and MIP models.

Example usage:

  model.computeIIS()
  model.write("model.ilp")