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#include <getopt.h>
#include <iostream>
#include <chrono>
#include <wolff_models/height.hpp>
#include <wolff_models/dihedral_inf.hpp>
#include <wolff.hpp>
#include "simple_measurement.hpp"
int main(int argc, char *argv[]) {
// set defaults
unsigned N = (unsigned)1e4;
unsigned D = 2;
unsigned L = 128;
double T = 0.8;
double H = 0.0;
int opt;
// take command line arguments
while ((opt = getopt(argc, argv, "N:D:L:T:H:")) != -1) {
switch (opt) {
case 'N': // number of steps
N = (unsigned)atof(optarg);
break;
case 'D': // dimension
D = atoi(optarg);
break;
case 'L': // linear size
L = atoi(optarg);
break;
case 'T': // temperature
T = atof(optarg);
break;
case 'H': // external field
H = atof(optarg);
break;
default:
exit(EXIT_FAILURE);
}
}
// define the spin-spin coupling
std::function <double(const height_t<long long>&, const height_t<long long>&)> Z = [] (const height_t<long long>& s1, const height_t<long long>& s2) -> double {
return - pow(s1.x - s2.x, 2);
};
// define the spin-field coupling
std::function <double(const height_t<long long>&)> B = [&] (const height_t<long long>& s) -> double {
return - H * pow(s.x, 2);
};
// initialize the lattice
graph<> G(D, L);
// initialize the system
wolff::system<dihedral_inf_t<long long>, height_t<long long>, graph<>> S(G, T, Z, B);
bool odd_run = false;
std::function <dihedral_inf_t<long long>(std::mt19937&, const wolff::system<dihedral_inf_t<long long>, height_t<long long>, graph<>>&, const graph<>::vertex&)> gen_R_IH = [&](std::mt19937& r, const wolff::system<dihedral_inf_t<long long>, height_t<long long>, graph<>>& S, const graph<>::vertex &v) -> dihedral_inf_t<long long> {
dihedral_inf_t<long long> rot;
rot.is_reflection = true;
if (odd_run) {
std::uniform_int_distribution<unsigned> dist(0, S.nv - 2);
unsigned j = v.ind;
//while (S.s[j].x == S.s[i0].x) {
unsigned tmp = dist(r);
if (tmp < v.ind) {
j = tmp;
} else {
j = tmp + 1;
}
//}
rot.x = 2 * S.s[j].x;
} else {
std::uniform_int_distribution<int> dist(0, 1);
int j = dist(r);
if (j) {
rot.x = 2 * S.s[v.ind].x + 1;
} else {
rot.x = 2 * S.s[v.ind].x - 1;
}
}
odd_run = !odd_run;
return rot;
};
// initailze the measurement object
simple_measurement A(S);
// initialize the random number generator
auto seed = std::chrono::high_resolution_clock::now().time_since_epoch().count();
std::mt19937 rng(seed);
// run wolff N times
S.run_wolff(N, gen_R_IH, A, rng);
// print the result of our measurements
std::cout << "Wolff complete!\nThe average energy per site was " << A.avgE() / S.nv
<< ".\nThe average magnetization per site was " << A.avgM() / S.nv
<< ".\nThe average cluster size per site was " << A.avgC() / S.nv << ".\n";
// exit
return 0;
}
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