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#include <getopt.h>
#include <iostream>
#include <chrono>
#define WOLFF_SITE_DEPENDENCE
#include "simple_measurement.hpp"
#include <wolff/models/ising.hpp>
#include <wolff.hpp>
using namespace wolff;
int main(int argc, char *argv[]) {
// set defaults
N_t N = (N_t)1e4;
D_t D = 2;
L_t L = 128;
double T = 2.26918531421;
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 = (N_t)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 ising_t&, const ising_t&)> Z = [] (const ising_t& s1, const ising_t& s2) -> double {
return (double)(s1 * s2);
};
// initialize the lattice
graph G(D, L);
// initialize the random number generator
auto seed = std::chrono::high_resolution_clock::now().time_since_epoch().count();
std::mt19937 rng{seed};
// define the spin-field coupling
std::vector<double> H_vals(G.nv);
std::normal_distribution<double> distribution(0.0, H);
for (v_t i = 0; i < G.nv; i++) {
H_vals[i] = distribution(rng);
}
std::function <double(v_t, const ising_t&)> B = [&] (v_t i, const ising_t& s) -> double {
return H_vals[i] * s;
};
// initialize the system
system<ising_t, ising_t> S(G, T, Z, B);
// define function that generates self-inverse rotations
std::function <ising_t(std::mt19937&, const system<ising_t, ising_t>&, v_t)> gen_r = gen_ising;
// initailze the measurement object
simple_measurement A(S);
// run wolff N times
S.run_wolff(N, gen_r, 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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