/**
* Create a propagator on real variables, propagated using IBEX. <br>
* A constraint is defined using <code>functions</code>. A function is a string declared using the
* following format: <br>
* - the '{i}' tag defines a variable, where 'i' is an explicit index the array of variables
* <code>vars</code>, <br>
* - one or more operators :'+,-,*,/,=,<,>,<=,>=,exp( ),ln( ),max( ),min( ),abs( ),cos( ), sin(
* ),...' <br>
* A complete list is available in the documentation of IBEX.
*
* <p>
*
* <p>
*
* <blockquote>
*
* <pre>
* new RealConstraint("({0}*{1})+sin({0})=1.0;ln({0}+[-0.1,0.1])>=2.6", new RealVar[]{x,y}, new String[]{""}, solver);
* </pre>
*
* </blockquote>
*
* @param functions list of functions, separated by a semi-colon
* @param vars array of variables
* @param options list of options to give to IBEX
*/
public RealPropagator(String functions, RealVar[] vars, int options) {
super(vars, PropagatorPriority.LINEAR, false);
this.ibex = solver.getIbex();
this.functions = functions;
this.option = options;
this.contractorIdx = ibex.add_contractor(vars.length, functions, option);
}
@Override
public void propagate(int evtmask) throws ContradictionException {
double domains[] = new double[2 * vars.length];
for (int i = 0; i < vars.length; i++) {
domains[2 * i] = vars[i].getLB();
domains[2 * i + 1] = vars[i].getUB();
}
int result = ibex.contract(contractorIdx, domains);
switch (result) {
case Ibex.FAIL:
contradiction(null, "Ibex failed");
case Ibex.CONTRACT:
for (int i = 0; i < vars.length; i++) {
vars[i].updateBounds(domains[2 * i], domains[2 * i + 1], aCause);
}
break;
case Ibex.ENTAILED:
for (int i = 0; i < vars.length; i++) {
vars[i].updateBounds(domains[2 * i], domains[2 * i + 1], aCause);
}
setPassive();
break;
case Ibex.NOT_SIGNIFICANT:
default:
}
}
@Override
public ESat isEntailed() {
double domains[] = new double[2 * vars.length];
for (int i = 0; i < vars.length; i++) {
domains[2 * i] = vars[i].getLB();
domains[2 * i + 1] = vars[i].getUB();
}
int result = ibex.contract(contractorIdx, domains);
if (result == Ibex.FAIL) {
return ESat.FALSE;
}
if (result == Ibex.ENTAILED || isCompletelyInstantiated()) {
for (int i = 0; i < vars.length; i++) {
if (vars[i].getLB() < domains[2 * i] || vars[i].getUB() > domains[2 * i + 1]) {
if (domains[2 * i + 1] - domains[2 * i] >= vars[i].getPrecision()) {
return ESat.UNDEFINED;
} else {
return ESat.FALSE;
}
}
}
return ESat.TRUE;
}
return ESat.UNDEFINED;
}
