void Optimizer::contract_and_bound(Cell& c, const IntervalVector& init_box) {
/*======================== contract y with y<=loup ========================*/
Interval& y=c.box[ext_sys.goal_var()];
// IntervalVector tmp_box(n);
// read_ext_box(c.box,tmp_box);
double ymax;
if (loup==POS_INFINITY) ymax=POS_INFINITY;
else ymax= compute_ymax()+1.e-15;
// else ymax= compute_ymax();
/*
if (!(y.ub() == ymax))
y &= Interval(NEG_INFINITY,ymax+1.e-15);
else if (y.ub()==ymax && !(tmp_box.contains(loup_point)))
y = Interval(y.lb(), ymax+1.e-15);
*/
y &= Interval(NEG_INFINITY,ymax);
if (y.is_empty()) {
c.box.set_empty();
return;
}
/*================ contract x with f(x)=y and g(x)<=0 ================*/
//cout << " [contract] x before=" << c.box << endl;
//cout << " [contract] y before=" << y << endl;
ctc.contract(c.box);
if (c.box.is_empty()) return;
//cout << " [contract] x after=" << c.box << endl;
//cout << " [contract] y after=" << y << endl;
// TODO: no more cell in argument here (just a box). Does it matter?
/*====================================================================*/
/*========================= update loup =============================*/
IntervalVector tmp_box(n);
read_ext_box(c.box,tmp_box);
entailed = &c.get<EntailedCtr>();
if (!update_entailed_ctr(tmp_box)) {
c.box.set_empty();
return;
}
bool loup_ch=update_loup(tmp_box);
// update of the upper bound of y in case of a new loup found
if (loup_ch) y &= Interval(NEG_INFINITY,compute_ymax());
loup_changed |= loup_ch;
if (y.is_empty()) { // fix issue #44
c.box.set_empty();
return;
}
/*====================================================================*/
// [gch] The case (!c.box.is_bisectable()) seems redundant
// with the case of a NoBisectableVariableException in
// optimize(). Is update_uplo_of_epsboxes called twice in this case?
// (bn] NO , the NoBisectableVariableException is raised by the bisector, there are 2 different cases of a non bisected box that may cause an update of uplo_of_epsboxes
if ((tmp_box.max_diam()<=prec && y.diam() <=goal_abs_prec) || !c.box.is_bisectable()) {
// rem1: tmp_box and not c.box because y is handled with goal_rel_prec and goal_abs_prec
// rem2: do not use a precision contractor here since it would make the box empty (and y==(-inf,-inf)!!)
// rem 3 : the extended boxes with no bisectable domains should be caught for avoiding infinite bisections
update_uplo_of_epsboxes(y.lb());
c.box.set_empty();
return;
}
//gradient=0 contraction for unconstrained optimization ;
//first order test for constrained optimization (useful only when there are no equations replaced by inequalities)
//works with the box without the objective (tmp_box)
firstorder_contract(tmp_box,init_box);
if (tmp_box.is_empty()) {
c.box.set_empty();
} else {
// the current extended box in the cell is updated
write_ext_box(tmp_box,c.box);
}
}
void Optimizer::contract_and_bound(Cell& c, const IntervalVector& init_box) {
// cout << "box " <<c.box << endl;
/*======================== contract y with y<=loup ========================*/
Interval& y=c.box[ext_sys.goal_var()];
double ymax;
if (loup==POS_INFINITY) ymax=POS_INFINITY;
else ymax= compute_ymax();
y &= Interval(NEG_INFINITY,ymax);
if (y.is_empty()) {
c.box.set_empty();
throw EmptyBoxException();
}
/*================ contract x with f(x)=y and g(x)<=0 ================*/
// cout << "y=f(x) and g(x)<=0 " << endl;
// cout << " x before=" << c.box << endl;
// cout << " y before=" << y << endl;
contract(c.box, init_box);
// cout << " x after=" << c.box << endl;
// cout << " y after=" << y << endl;
// TODO: no more cell in argument here (just a box). Does it matter?
/*====================================================================*/
/*========================= update loup =============================*/
IntervalVector tmp_box(n);
read_ext_box(c.box,tmp_box);
entailed = &c.get<EntailedCtr>();
update_entailed_ctr(tmp_box);
update_loup(tmp_box);
/*====================================================================*/
// [gch] TODO: the case (!c.box.is_bisectable()) seems redundant
// with the case of a NoBisectableVariableException in
// optimize(). Is update_uplo_of_epsboxes called twice in this case?
// (bn] NO , the NoBisectableVariableException is raised by the bisector,
// there are actually 2 different cases of a non bisected box that may cause an update
// of uplo_of_epsboxes
double tmp_diam =tmp_box.max_diam();
if ((tmp_diam<=prec && y.diam() <=goal_abs_prec) || !c.box.is_bisectable()) {
// rem1: tmp_box and not c.box because y is handled with goal_rel_prec and goal_abs_prec
// rem2: do not use a precision contractor here since it would make the box empty (and y==(-inf,-inf)!!)
// rem 3 : the extended boxes with no bisectable domains should be catched for avoiding infinite bisections
if (!(tmp_box.is_unbounded())) {
// rem4: this case can append if the interval [1.79769e+308,inf] is in c.box.
// It is only numerical degenerated case
update_uplo_of_epsboxes(y.lb());
}
throw EmptyBoxException();
}
//gradient=0 contraction for unconstrained optimization ;
//first order test for constrained optimization (useful only when there are no equations replaced by inequalities)
//works with the box without the objective (tmp_box)
firstorder_contract(tmp_box,init_box);
// the current extended box in the cell is updated
write_ext_box(tmp_box,c.box);
}
