XPRSiisall
XPRSiisall |
Purpose
Performs an automated search for independent Irreducible Infeasible Sets (IIS) in an infeasible problem.
Synopsis
int XPRS_CC XPRSiisall(XPRSprob prob);
Argument
|
prob
|
The current problem.
|
Related controls
Integer
|
Number of Irreducible Infeasible Sets to be found.
|
Example
This example searches for IISs and then questions the problem attribute
NUMIIS to determine how many were found:
int iis;
...
XPRSiisall(prob);
XPRSgetintattrib(prob, XPRS_NUMIIS, &iis);
printf("number of IISs = %d\n", iis);
Further information
2. A model may have several infeasibilities. Repairing a single IIS may not make the model feasible. For this reason the Optimizer can find an IIS for each of the infeasibilities in a model. If the control
MAXIIS is set to a positive integer value then the
XPRSiisall command will stop if
MAXIIS IISs have been found. By default the control
MAXIIS is set to
-1, in which case an IIS is found for each of the infeasibilities in the model.
3. The problem attribute
NUMIIS allows the user to recover the number of IISs found in a particular search. Alternatively, the
XPRSiisstatus function may be used to retrieve the number of IISs found by
XPRSiisfirst (
IIS),
XPRSiisnext (
IIS
-n) or
XPRSiisall (
IIS
-a) functions.
Related topics
XPRSgetiisdata,
XPRSiisclear,
XPRSiisfirst,
XPRSiisisolations,
XPRSiisnext,
XPRSiisstatus,
XPRSiiswrite,
IIS.