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Processed subhalo data and modified integrator to read and use new data structure

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Yohai Meiron 2020-04-26 22:51:52 -04:00
parent cb66caf6ba
commit f8eae117dd
4 changed files with 281 additions and 62 deletions
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103
main.cpp
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@ -1,6 +1,7 @@
#include <algorithm>
#include <array>
#include <boost/numeric/odeint.hpp>
#include <Eigen/Geometry>
#include <fstream>
#include <gsl/gsl_spline.h>
#include <iostream>
@ -11,7 +12,7 @@
#include "loadtxt.h"
using double3 = Eigen::Vector3d;
// Our units are {kiloparsec, solar mass, gigayear}
constexpr double G = 4.498317481097514e-06;
@ -41,52 +42,78 @@ private:
gsl_spline *spline;
};
class Plummer {
public:
Plummer(double M, double b)
: M(M), b(b) {}
void calc_acceleration(const double *pos, double *acc)
{
double r2 = (pos[0]*pos[0] + pos[1]*pos[1] + pos[2]*pos[2] + b*b);
double r = sqrt(r2);
double r3_inv = 1/(r*r2);
acc[0] = -G*M*pos[0]*r3_inv;
acc[1] = -G*M*pos[1]*r3_inv;
acc[2] = -G*M*pos[2]*r3_inv;
}
void plummer(double M, double b, const double3& pos, double3& acc)
{
double r2 = (pos[0]*pos[0] + pos[1]*pos[1] + pos[2]*pos[2] + b*b);
double r = sqrt(r2);
double r3_inv = 1/(r*r2);
acc = -G*M*pos*r3_inv;
}
private:
double M, b;
};
void miyamoto_nagai(double M, double a, double b, double phi, double theta, const double3& pos, double3& acc)
{
// Construct new z-axis from the angles
double cos_theta = cos(theta);
double sin_theta = sqrt(1-cos_theta*cos_theta);
double cos_phi = cos(phi);
double sin_phi = sqrt(1-cos_phi*cos_phi);
Eigen::Vector3d old_z_axis = {cos_phi*sin_theta, sin_phi*sin_theta, cos_theta};
// Construct rotation
auto rot = Eigen::Quaternion<double>::FromTwoVectors(old_z_axis, Eigen::Vector3d::UnitZ());
// Rotate the position vector
auto new_pos = rot * pos;
// Calculate acceleration in new frame
Eigen::Vector3d acc_in_rotated_frame;
auto z_tmp = sqrt(new_pos[2]*new_pos[2] + b*b);
auto r2_tmp = new_pos[0]*new_pos[0] + new_pos[1]*new_pos[1] + (z_tmp + a)*(z_tmp + a);
auto r_tmp = sqrt(r2_tmp);
auto tmp = G*M / (r2_tmp*r_tmp);
acc_in_rotated_frame[0] = - tmp * new_pos[0];
acc_in_rotated_frame[1] = - tmp * new_pos[1];
acc_in_rotated_frame[2] = - tmp * new_pos[2] * (z_tmp + a)/z_tmp;
// Return to original frame
acc = rot.inverse() * acc_in_rotated_frame;
}
class Galaxy {
public:
Galaxy(std::string file_name)
{
auto data = Loadtxt("file.dat", {1, 2, 3}).get_cols();
auto& t_data = data[0];
auto& halo_m_data = data[1];
auto& halo_b_data = data[2];
auto data = Loadtxt(file_name, {1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11}).get_cols();
auto& t_data = data[0];
std::transform(begin(t_data), end(t_data), begin(t_data), [t0=t_data[0]](const double& x){ return x-t0; });
std::transform(halo_b_data.begin(), halo_b_data.end(), halo_b_data.begin(), [](const double& x){ return x*0.7664209365408798; });
interp_halo_m = Interp(t_data, halo_m_data);
interp_halo_b = Interp(t_data, halo_b_data);
for (int i=0; i<10; i++) interp[i] = Interp(t_data, data[i+1]);
}
void func(const std::array<double, 6> &y, std::array<double, 6> &f, const double t)
{
double halo_m = interp_halo_m(t);
double halo_b = interp_halo_b(t);
Plummer plummer(halo_m, halo_b);
f[0] = y[3]; // vx -> x'
f[1] = y[4]; // vy -> y'
f[2] = y[5]; // vz -> z'
plummer.calc_acceleration(y.data(), f.data()+3); // a -> v'
double m_disk = interp[0](t);
double phi = interp[1](t);
double theta = interp[2](t);
double a_disk = interp[3](t);
double b_disk = interp[4](t);
double m_halo = interp[5](t);
double b_halo = interp[6](t);
double3 dalembert;
// for (int i=0; i<3; i++) dalembert[i] = interp[7+i](t);
dalembert = {0,0,0};
double3 acc_disk, acc_halo;
const double3 pos(y.data());
miyamoto_nagai(m_disk, a_disk, b_disk, phi, theta, pos, acc_disk);
plummer(m_halo, b_halo, pos, acc_halo);
for (int i=0; i<3; i++) f[3+i] = acc_disk[i] + acc_halo[i] + dalembert[i];
}
private:
Interp interp_halo_m;
Interp interp_halo_b;
} galaxy("file.dat");
Interp interp[10];
} galaxy("subhalo_411321_parameters_processed.dat");
extern "C"
int integrate(const double y0[], const double t_max, const double stride_size, double y[])
@ -113,14 +140,24 @@ int integrate(const double y0[], const double t_max, const double stride_size, d
}
int main()
{
std::cout << "Hi" << std::endl;
double y[12];
double y0[] = {80,0,0,0,80,0};
for (int i=0; i<8000; i++)
integrate(y0, 10, 10, y);
integrate(y0, 10, 10, y);
for (int i=0; i<12; i++) std::cout << y[i] << std::endl;
// double y[12];
// double y0[] = {80,0,0,0,80,0};
// for (int i=0; i<8000; i++)
// integrate(y0, 10, 10, y);
/*double y0[] = {80,0,0,0,80,0};
double y[12];