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author | Jaron Kent-Dobias <jaron@kent-dobias.com> | 2018-10-19 14:09:13 -0400 |
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committer | Jaron Kent-Dobias <jaron@kent-dobias.com> | 2018-10-19 14:09:13 -0400 |
commit | 48dbbcff78944628b56d98a663f682e91023245c (patch) | |
tree | 77912419432c3feaa6a7d5b19c4baa76a64eeb0e /examples/ising_random_field.cpp | |
parent | a3ad099281e0f608d0bcfda178502fb41acd8c5b (diff) | |
download | c++-48dbbcff78944628b56d98a663f682e91023245c.tar.gz c++-48dbbcff78944628b56d98a663f682e91023245c.tar.bz2 c++-48dbbcff78944628b56d98a663f682e91023245c.zip |
added examples for no field and site depedence
Diffstat (limited to 'examples/ising_random_field.cpp')
-rw-r--r-- | examples/ising_random_field.cpp | 93 |
1 files changed, 93 insertions, 0 deletions
diff --git a/examples/ising_random_field.cpp b/examples/ising_random_field.cpp new file mode 100644 index 0000000..b37b0ce --- /dev/null +++ b/examples/ising_random_field.cpp @@ -0,0 +1,93 @@ + +#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; +} + |