mc_weight_type Try() {
#ifdef DEBUG
std::cout << "I AM IN Try for Remove_Cdag_C_Delta" << std::endl;
std::cout << "CONFIG BEFORE: " << Config.DT << std::endl;
//for (int a = 0; a<Config.Na; ++a) print_det(Config.dets[a]);
#endif
// the det has to be recomputed each time, since global moves will change it
det = Config.dets[a_level];
// Pick up a couple of C, Cdagger to remove at random
const int Na(det->NumberOfC());
if (Na==0) return 0;
int numCdag = 1 + Random(Na);
int numC = 1 + Random(Na);
// det is in decreasing order.
numC = Na - numC + 1;
numCdag = Na - numCdag + 1;
// Remove the operators from the traces
// the -Na +1 is to move backward, to compare with V1 ...
Config.DT.removeTwoOperators(*det->select_Cdagger( numCdag ),
*det->select_C( numC ));
// Acceptance probability
mc_weight_type p = Config.DT.ratioNewTrace_OldTrace() * det->try_remove(numCdag,numC);
double Tratio = power(2*Nalpha* Config.Beta / double(2*Na) ,2);
#ifdef DEBUG
std::cout << "RATIO: " << Config.DT.ratioNewTrace_OldTrace() << std::endl;
std::cout << "CONFIG AFTER: " << Config.DT << std::endl;
//for (int a = 0; a<Config.Na; ++a) print_det(Config.dets[a]);
#endif
return p/Tratio;
}
