| #include <math.h> |
| #include <stdlib.h> |
| #include <string.h> |
| #include <gsl/gsl_siman.h> |
| |
| /* set up parameters for this simulated annealing run */ |
| |
| /* how many points do we try before stepping */ |
| #define N_TRIES 200 |
| |
| /* how many iterations for each T? */ |
| #define ITERS_FIXED_T 1000 |
| |
| /* max step size in random walk */ |
| #define STEP_SIZE 1.0 |
| |
| /* Boltzmann constant */ |
| #define K 1.0 |
| |
| /* initial temperature */ |
| #define T_INITIAL 0.008 |
| |
| /* damping factor for temperature */ |
| #define MU_T 1.003 |
| #define T_MIN 2.0e-6 |
| |
| gsl_siman_params_t params |
| = {N_TRIES, ITERS_FIXED_T, STEP_SIZE, |
| K, T_INITIAL, MU_T, T_MIN}; |
| |
| /* now some functions to test in one dimension */ |
| double E1(void *xp) |
| { |
| double x = * ((double *) xp); |
| |
| return exp(-pow((x-1.0),2.0))*sin(8*x); |
| } |
| |
| double M1(void *xp, void *yp) |
| { |
| double x = *((double *) xp); |
| double y = *((double *) yp); |
| |
| return fabs(x - y); |
| } |
| |
| void S1(const gsl_rng * r, void *xp, double step_size) |
| { |
| double old_x = *((double *) xp); |
| double new_x; |
| |
| double u = gsl_rng_uniform(r); |
| new_x = u * 2 * step_size - step_size + old_x; |
| |
| memcpy(xp, &new_x, sizeof(new_x)); |
| } |
| |
| void P1(void *xp) |
| { |
| printf ("%12g", *((double *) xp)); |
| } |
| |
| int |
| main(int argc, char *argv[]) |
| { |
| const gsl_rng_type * T; |
| gsl_rng * r; |
| |
| double x_initial = 15.5; |
| |
| gsl_rng_env_setup(); |
| |
| T = gsl_rng_default; |
| r = gsl_rng_alloc(T); |
| |
| gsl_siman_solve(r, &x_initial, E1, S1, M1, P1, |
| NULL, NULL, NULL, |
| sizeof(double), params); |
| |
| gsl_rng_free (r); |
| return 0; |
| } |