File indexing completed on 2024-09-29 06:26:38

0001 #include <fstream>
0002 #include <iostream>
0003 #include <math.h>
0004 
0005 #include <gsl/gsl_randist.h>
0006 #include <gsl/gsl_rng.h>
0007 
0008 int main() {
0009     std::string fileName = "out_1M_5pathes.bin";
0010     int count = 1000000;
0011     int pathes = 5;
0012 
0013     double delta = 0.25;
0014     int dt = 1;
0015     double sigma = std::pow(delta, 2) * dt;
0016     double path[pathes] = {0.0};
0017 
0018     std::ofstream ostrm(fileName, std::ios::binary);
0019 
0020     // create a generator chosen by the environment variable GSL_RNG_TYPE
0021     gsl_rng_env_setup();
0022     const gsl_rng_type* T = gsl_rng_default;
0023     gsl_rng* r = gsl_rng_alloc(T);
0024     gsl_rng_set(r, 12345);
0025 
0026     // data
0027     for (int i = 0; i < count; ++i) {
0028         double x = i * dt;
0029         ostrm.write(reinterpret_cast<char*>(&x), sizeof(double));
0030 
0031         for (int p = 0; p < pathes; ++p) {
0032             path[p] += gsl_ran_gaussian(r, sigma);
0033             ostrm.write(reinterpret_cast<char*>(&path[p]), sizeof(double));
0034         }
0035     }
0036 }