4fd800b3a8 2011-02-23        kinaba: // ternery search (for shita-ni-totsu)
4fd800b3a8 2011-02-23        kinaba: {
4fd800b3a8 2011-02-23        kinaba: 	double x = ~min~;
4fd800b3a8 2011-02-23        kinaba: 	double w = ~max~;
4fd800b3a8 2011-02-23        kinaba: 	for(int i=0; i<~iteration~; ++i) // or, while( w-x > ~eps~ ) be careful for precision!
4fd800b3a8 2011-02-23        kinaba: 	{
4fd800b3a8 2011-02-23        kinaba: 		double y = 2*x/3 + w/3;
4fd800b3a8 2011-02-23        kinaba: 		double z = x/3 + 2*w/3;
4fd800b3a8 2011-02-23        kinaba: 		double fx = f(x);
4fd800b3a8 2011-02-23        kinaba: 		double fy = f(y);
4fd800b3a8 2011-02-23        kinaba: 		double fz = f(z);
4fd800b3a8 2011-02-23        kinaba: 		double fw = f(w);
4fd800b3a8 2011-02-23        kinaba: 		if( fx < fy )      w = y;
4fd800b3a8 2011-02-23        kinaba: 		else if( fz > fw ) x = z;
4fd800b3a8 2011-02-23        kinaba: 		else if( fy < fz ) w = z;
4fd800b3a8 2011-02-23        kinaba: 		else               x = y;
4fd800b3a8 2011-02-23        kinaba: 	}
4fd800b3a8 2011-02-23        kinaba: }