C++ (Cpp) IntervalVector::lb Examples

Example #1

File: ibex_utils.cpp Project: ibex-team/ibex-lib

Interval centeredFormEval(const Function& function, const IntervalVector& arg) {
	/*Interval natural_extension = function.eval(arg);
	Interval centered_form = function.eval(arg.mid()) + function.gradient(arg) * (arg - arg.mid());*/
	IntervalVector new_arg_ub(arg);
	IntervalVector new_arg_lb(arg);
	IntervalVector grad = function.gradient(arg);
	for(int i = 0; i < arg.size(); ++i) {
		if(grad[i].lb() > 0) {
			new_arg_ub[i] = arg[i].ub();
			new_arg_lb[i] = arg[i].lb();
		} else if(grad[i].ub() < 0) {
			new_arg_ub[i] = arg[i].lb();
			new_arg_lb[i] = arg[i].ub();
		}
	}
	Interval natural_extension = function.eval(arg);
	Interval centered_form = function.eval(arg.mid()) + grad * (arg - arg.mid());
	Interval ub_form = function.eval(arg.ub()) + grad * (arg - arg.ub());
	Interval lb_form = function.eval(arg.lb()) + grad * (arg - arg.lb());
	Interval res = natural_extension & centered_form & ub_form & lb_form;
	res &= Interval(function.eval(new_arg_lb).lb(), function.eval(new_arg_ub).ub());
	return res;
}