Initializing help system before first use

problem.IISStatus

Purpose
Returns statistics on the Irreducible Infeasible Sets (IIS) found so far by problem.firstIIS, problem.nextIIS or problem.IISAll.
Topic area
Infeasibility
Synopsis
niis, nrows, ncols, suminfeas, numinfeas = problem.IISStatus()
Return value
niis 
The number of IISs found so far.
nrows 
Array containing the number of rows in each IIS.
ncols 
Array containing the number of bounds in each IIS.
suminfeas 
Array containing the sum of infeasibilities in each IIS after the first phase simplex.
numinfeas 
Array containing the number of infeasible variables in each IIS after the first phase simplex.
Further information
1. The arrays are 0 based, index 0 corresponding to the initial infeasible subproblem.
2. For the initial infeasible problem (IIS 0) the subproblem size is returned (which may be different from the number of bounds), while for the IISs the number of bounds is returned (usually much smaller than the number of columns in the IIS).
3. Note that the values in suminfeas and numinfeas depend on the IIS, and in turn on the basis where the simplex algorithm has stopped. Different IISs can have different error measures.
4. niis is set to -1 if the search for IISs has not yet started.
Related topics
problem.getIISData, problem.IISAll, problem.clearIIS, problem.firstIIS, problem.IISIsolations, problem.nextIIS, problem.printIIS, problem.writeIIS

Parent Topic Methods of the class problem

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