tfaour/OrbitalSimulator
1
0
Fork 0
Code Issues 4 Pull Requests Actions Packages Projects Releases Wiki Activity

Merge pull request 'rust_rewrite' (#11) from rust_rewrite into main

Browse Source 
Reviewed-on: #11
This commit is contained in:
tfaour 2025-06-19 23:42:19 -04:00
commit bd99aca317
24 changed files with 413 additions and 1225 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

14
.gitignore vendored
View File

@ -4,4 +4,16 @@ __pycache__
/build /build
/cmake-build-* /cmake-build-*
CMakeFiles/ CMakeFiles/
*.cmake *.cmake
/rust/target
/rust/target/*
rust/Cargo.lock
out.out
output.json
*.png
# Added by cargo
/target
Cargo.lock

85
CMakeLists.txt
View File

@ -1,85 +0,0 @@
cmake_minimum_required(VERSION 3.10)
project(orbital_simulator)
set(CMAKE_CXX_STANDARD 23)
set(CMAKE_CXX_STANDARD_REQUIRED ON)
# Enable testing
enable_testing()
include(CTest)
# Find required packages
find_package(Boost REQUIRED COMPONENTS program_options)
find_package(nlohmann_json REQUIRED)
find_package(GTest REQUIRED)
# Add source files
set(SOURCES
src/main.cpp
src/body.cpp
src/calc.cpp
src/simulator.cpp
)
# Add source files for tests (excluding main.cpp)
set(TEST_SOURCES
src/body.cpp
src/calc.cpp
src/simulator.cpp
)
# Add header files
set(HEADERS
src/body.hpp
src/calc.hpp
src/simulator.hpp
src/units.hpp
)
# Create main executable
add_executable(orbital_simulator ${SOURCES} ${HEADERS})
# Create test executable
add_executable(orbital_simulator_tests
tests/body_test.cpp
tests/calc_test.cpp
tests/simulator_test.cpp
${TEST_SOURCES} # Use test sources instead of all sources
)
# Link libraries for main executable
target_link_libraries(orbital_simulator
PRIVATE
Boost::program_options
nlohmann_json::nlohmann_json
)
# Link libraries for test executable
target_link_libraries(orbital_simulator_tests
PRIVATE
GTest::GTest
GTest::Main
)
# Include directories
target_include_directories(orbital_simulator
PRIVATE
${CMAKE_SOURCE_DIR}/src
)
target_include_directories(orbital_simulator_tests
PRIVATE
${CMAKE_SOURCE_DIR}/src
${CMAKE_SOURCE_DIR}/tests
)
# Add tests to CTest
add_test(NAME orbital_simulator_tests COMMAND orbital_simulator_tests)
# Optional: Enable ncurses for terminal plotting
option(ENABLE_NCURSES "Enable terminal plotting with ncurses" OFF)
if(ENABLE_NCURSES)
find_package(Curses REQUIRED)
target_compile_definitions(orbital_simulator PRIVATE NCURSES_ENABLED)
target_link_libraries(orbital_simulator PRIVATE ${CURSES_LIBRARIES})
endif()

19
Cargo.toml Normal file
View File

@ -0,0 +1,19 @@
[package]
name = "orbital_simulator"
version = "0.1.0"
edition = "2021"
authors = ["thomas"]
# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
[dependencies]
bincode = "1.3"
clap = { version = "4.5.39", features = ["derive"] }
env_logger = "0.11.8"
glam = { version = "0.30.4", features = ["serde"] }
humantime = "2.2.0"
indicatif = "0.17.11"
log = "0.4.27"
once_cell = "1.21.3"
serde = { version = "1.0.219", features = ["derive"] }
serde_json = "1.0.140"

83
README.md
View File

@ -1,83 +0,0 @@
# Orbital Simulator
A C++ implementation of an N-body orbital simulator with high-precision calculations.
## Dependencies
- C++17 compatible compiler
- CMake 3.10 or higher
- Boost library (for high-precision decimal arithmetic)
- Optional: ncurses (for terminal plotting)
## Building
1. Create a build directory:
```bash
mkdir build
cd build
```
2. Configure with CMake:
```bash
cmake ..
```
3. Build the project:
```bash
make
```
To enable terminal plotting with ncurses, configure with:
```bash
cmake -DENABLE_NCURSES=ON ..
```
## Usage
The simulator can be used to simulate orbital mechanics with high precision. The main components are:
- `Body`: Represents a celestial body with position, velocity, and mass
- `Simulator`: Manages the simulation of multiple bodies
- `units.hpp`: Contains physical constants and unit conversion utilities
Example usage:
```cpp
#include "simulator.hpp"
#include "units.hpp"
int main() {
// Create bodies
std::vector<Body> bodies;
// Earth
Position earth_pos{Decimal(0), Decimal(0), Decimal(0)};
Velocity earth_vel{Decimal(0), Decimal(0), Decimal(0)};
bodies.emplace_back(earth_pos, earth_vel, EARTH_MASS, "Earth");
// Moon
Position moon_pos{AU, Decimal(0), Decimal(0)};
Velocity moon_vel{Decimal(0), MOON_ORBITAL_VELOCITY, Decimal(0)};
bodies.emplace_back(moon_pos, moon_vel, MOON_MASS, "Moon");
// Create simulator
Simulator sim(bodies, 0.1, 100, "output.txt");
// Run simulation
sim.run(1000);
return 0;
}
```
## Features
- High-precision decimal arithmetic using Boost.Multiprecision
- N-body gravitational simulation
- Progress tracking and checkpointing
- Optional terminal visualization
- Configurable simulation parameters
## License
This project is open source and available under the MIT License.

165
animate.py
View File

@ -1,165 +0,0 @@
#!/usr/bin/env python3
import numpy as np
import matplotlib.pyplot as plt
from matplotlib.animation import FuncAnimation
from collections import defaultdict
import argparse
import re
def parse_line(line):
"""Parse a line from the simulation output."""
# Skip comments and empty lines
if line.startswith('#') or not line.strip():
return None
# Parse the line format: body_name: X = x1m x2m x3m, V = v1m/s v2m/s v3m/s
try:
# Split on colon to separate name and data
name_part, data_part = line.strip().split(':')
name = name_part.strip()
# Split data part into position and velocity
pos_part, vel_part = data_part.split(',')
# Extract position values
pos_str = pos_part.split('=')[1].strip()
pos_values = [float(x.replace('m', '').strip()) for x in pos_str.split() if x.strip()]
if len(pos_values) != 3:
return None
return {
'name': name,
'position': tuple(pos_values)
}
except (ValueError, IndexError):
return None
def read_output_file(filename):
"""Read the simulation output file and organize data by body and time."""
positions = defaultdict(list)
times = [] # We'll use frame numbers as times since actual time isn't in output
with open(filename, 'r') as f:
frame = 0
for line in f:
data = parse_line(line)
if data is None:
continue
name = data['name']
pos = data['position']
# Store position
positions[name].append((pos[0], pos[1]))
frame += 1
times.append(frame)
return positions, times
def center_positions(positions, center_body):
"""Center all positions relative to the specified body."""
if center_body not in positions:
print(f"Warning: Center body '{center_body}' not found in simulation")
return positions
centered_positions = defaultdict(list)
for frame in range(len(next(iter(positions.values())))):
# Get center body position for this frame
center_pos = positions[center_body][frame]
# Shift all positions relative to center body
for name, pos_list in positions.items():
if frame < len(pos_list):
pos = pos_list[frame]
centered_pos = (pos[0] - center_pos[0], pos[1] - center_pos[1])
centered_positions[name].append(centered_pos)
return centered_positions
def create_animation(positions, times, output_file=None, center_body=None):
"""Create an animation of the bodies' orbits."""
# Check if we have any data
if not positions or not times:
print("Error: No valid data found in the input file")
return
# Center positions if requested
if center_body:
positions = center_positions(positions, center_body)
# Set up the figure and axis
fig, ax = plt.subplots(figsize=(10, 10))
# Set equal aspect ratio
ax.set_aspect('equal')
# Create scatter plots for each body
scatters = {}
for name in positions.keys():
scatters[name], = ax.plot([], [], 'o-', label=name, alpha=0.7)
# Set up the plot
ax.set_xlabel('X (m)')
ax.set_ylabel('Y (m)')
title = 'Orbital Simulation'
if center_body:
title += f' (centered on {center_body})'
ax.set_title(title)
ax.legend()
# Find the bounds of the plot
all_x = []
all_y = []
for pos_list in positions.values():
if pos_list: # Only process if we have positions
x, y = zip(*pos_list)
all_x.extend(x)
all_y.extend(y)
if not all_x or not all_y:
print("Error: No valid position data found")
return
max_range = max(max(abs(min(all_x)), abs(max(all_x))),
max(abs(min(all_y)), abs(max(all_y))))
ax.set_xlim(-max_range, max_range)
ax.set_ylim(-max_range, max_range)
def init():
"""Initialize the animation."""
for scatter in scatters.values():
scatter.set_data([], [])
return list(scatters.values())
def update(frame):
"""Update the animation for each frame."""
for name, scatter in scatters.items():
if positions[name]: # Only update if we have positions
x, y = zip(*positions[name][:frame+1])
scatter.set_data(x, y)
return list(scatters.values())
# Create the animation
anim = FuncAnimation(fig, update, frames=len(times),
init_func=init, blit=True,
interval=50) # 50ms between frames
if output_file:
anim.save(output_file, writer='ffmpeg', fps=30)
else:
plt.show()
def main():
parser = argparse.ArgumentParser(description='Animate orbital simulation output')
parser.add_argument('input_file', help='Input file from simulation')
parser.add_argument('--output', '-o', help='Output video file (optional)')
parser.add_argument('--center', '-c', help='Center the animation on this body')
args = parser.parse_args()
positions, times = read_output_file(args.input_file)
create_animation(positions, times, args.output, args.center)
if __name__ == '__main__':
main()

22
config/jwst.json Normal file
View File

@ -0,0 +1,22 @@
{
"bodies": [
{
"name": "Earth",
"mass": 5.972e24,
"position": [1.47095e11, 0, 0],
"velocity": [0, 29290, 0]
},
{
"name": "Sun",
"mass": 1.989e30,
"position": [0, 0, 0],
"velocity": [0, 0, 0]
},
{
"name": "JWST",
"mass": 6500,
"position": [149217067274.40607, 0, 0],
"velocity": [0, 29729.784, 0]
}
]
}

78
src/body.cpp
View File

@ -1,78 +0,0 @@
#include "body.hpp"
#include "calc.hpp"
#include <cmath>
#include <ranges>
Body::Body(const Position& X, const Velocity& V, const Mass& m, const std::string& name)
: X(X), V(V), m(m), name(name) {
A = Acceleration{Decimal(0), Decimal(0), Decimal(0)};
}
void Body::addAcceleration(const Acceleration& new_A) {
for (const auto& [new_a, cur_a]: std::views::zip(new_A, this->A)){
cur_a += new_a;
}
}
void Body::subAcceleration(const Acceleration& new_A) {
for (const auto& [new_a, cur_a]: std::views::zip(new_A, this->A)){
cur_a -= new_a;
}
}
std::tuple<Position, Velocity, Mass> Body::save() const {
return std::make_tuple(X, V, m);
}
Body Body::load(const std::tuple<Position, Velocity, Mass>& tup) {
return Body(std::get<0>(tup), std::get<1>(tup), std::get<2>(tup));
}
void Body::step(Decimal step_size) {
for (int i = 0; i < 3; ++i) {
X[i] += step_size * V[i];
V[i] += step_size * A[i];
A[i] = Decimal(0);
}
}
Decimal Body::E() const {
return ke() + pe();
}
Decimal Body::pe() const {
return -m / dist_from_o();
}
Decimal Body::dist_from_o() const {
Decimal sum = Decimal(0);
for (const auto& x : X) {
sum += x * x;
}
return std::sqrt(sum);
}
Decimal Body::ke() const {
return Decimal(0.5) * m * (_speed() * _speed());
}
Decimal Body::_speed() const {
Decimal sum = Decimal(0);
for (const auto& v : V) {
sum += v * v;
}
return std::sqrt(sum);
}
std::string Body::speed() const {
return format_sig_figs(real_vel(_speed()), 5);
}
std::string Body::toString() const {
std::string pos_str, vel_str;
for (int i = 0; i < 3; ++i) {
pos_str += format_sig_figs(real_pos(X[i]), 10) + "m ";
vel_str += format_sig_figs(real_vel(V[i]), 10) + "m/s ";
}
return name + ": X = " + pos_str + ", V = " + vel_str;
}

48
src/body.hpp
View File

@ -1,48 +0,0 @@
#pragma once
#include "units.hpp"
#include <string>
#include <tuple>
#include <memory>
class Body {
public:
Body(const Position& X, const Velocity& V, const Mass& m,
const std::string& name = "");
// Save and load state
std::tuple<Position, Velocity, Mass> save() const;
static Body load(const std::tuple<Position, Velocity, Mass>& tup);
// Physics calculations
void step(Decimal step_size);
Decimal E() const; // Total energy
Decimal pe() const; // Potential energy
Decimal ke() const; // Kinetic energy
Decimal dist_from_o() const; // Distance from origin
std::string speed() const; // Speed as formatted string
// Getters
const Position& getPosition() const { return X; }
const Velocity& getVelocity() const { return V; }
const Acceleration& getAcceleration() const { return A; }
const Mass& getMass() const { return m; }
const std::string& getName() const { return name; }
// Setters
void setAcceleration(const Acceleration& new_A) { A = new_A; }
void addAcceleration(const Acceleration& new_A);
void subAcceleration(const Acceleration& new_A);
// String representation
std::string toString() const;
private:
Position X;
Velocity V;
Acceleration A;
Mass m;
std::string name;
Decimal _speed() const; // Internal speed calculation
};

147
src/calc.cpp
View File

@ -1,147 +0,0 @@
#include "calc.hpp"
#include <cmath>
#include <iostream>
#include <iomanip>
#include <sstream>
#include <boost/multiprecision/cpp_dec_float.hpp>
std::vector<std::vector<Decimal>> calculate_distances(const std::vector<Position>& positions) {
int N = positions.size();
std::vector<std::vector<Decimal>> dists(N, std::vector<Decimal>(N, Decimal(0)));
for (int i = 0; i < N; ++i) {
for (int j = i + 1; j < N; ++j) {
Decimal sum = Decimal(0);
for (int k = 0; k < 3; ++k) {
Decimal diff = positions[i][k] - positions[j][k];
sum += diff * diff;
}
Decimal d = std::sqrt(sum);
dists[i][j] = d;
dists[j][i] = d;
}
}
return dists;
}
std::string format_sig_figs(Decimal value, int sig_figs) {
if (value == 0) {
return "0";
}
std::stringstream ss;
ss << std::scientific << std::setprecision(sig_figs - 1) << value;
return ss.str();
}
void print_progress_bar(int iteration, int total, std::chrono::time_point<std::chrono::steady_clock> start_time, int length, Decimal step_size) {
float percent = (float)iteration / total * 100;
int filled_length = length * iteration / total;
std::string bar;
bar.reserve(length + 1);
bar += '[';
bar.append(filled_length, '#');
bar.append(length - filled_length, '-');
bar += ']';
auto now = std::chrono::steady_clock::now();
auto elapsed = std::chrono::duration_cast<std::chrono::seconds>(now - start_time).count();
double steps_per_second = elapsed > 0 ? real_time(Decimal(iteration) * step_size) / elapsed : 0;
// Determine appropriate time unit
std::string time_unit;
if (steps_per_second >= 3600) {
time_unit = "hour/s";
steps_per_second /= 3600;
} else if (steps_per_second >= 60) {
time_unit = "min/s";
steps_per_second /= 60;
} else {
time_unit = "s/s";
}
// Clear the current line and move cursor to start
std::cout << "\r\033[K";
// Print the progress bar
std::cout << bar << " " << std::fixed << std::setprecision(2)
<< percent << "% " << std::setprecision(1) << steps_per_second << " " << time_unit << std::flush;
}
#ifdef NCURSES_ENABLED
void plot_points_terminal(const std::vector<Position>& vectors, WINDOW* stdscr,
Decimal scale, int grid_width, int grid_height) {
if (vectors.empty()) {
mvwaddstr(stdscr, 0, 0, "No vectors provided.");
wrefresh(stdscr);
return;
}
// Scale and round vectors
std::vector<std::pair<int, int>> scaled_vectors;
for (const auto& vec : vectors) {
scaled_vectors.emplace_back(
std::round(vec[0] / scale),
std::round(vec[1] / scale)
);
}
// Find bounds
int min_x = scaled_vectors[0].first;
int max_x = min_x;
int min_y = scaled_vectors[0].second;
int max_y = min_y;
for (const auto& vec : scaled_vectors) {
min_x = std::min(min_x, vec.first);
max_x = std::max(max_x, vec.first);
min_y = std::min(min_y, vec.second);
max_y = std::max(max_y, vec.second);
}
// Center offsets
int center_x = (grid_width / 2) - min_x;
int center_y = (grid_height / 2) - min_y;
// Adjust coordinates
std::vector<std::pair<int, int>> adjusted_vectors;
for (const auto& vec : scaled_vectors) {
adjusted_vectors.emplace_back(
vec.first + center_x,
vec.second + center_y
);
}
// Get terminal bounds
int max_terminal_y, max_terminal_x;
getmaxyx(stdscr, max_terminal_y, max_terminal_x);
max_x = std::min(grid_width, max_terminal_x - 5);
max_y = std::min(grid_height, max_terminal_y - 5);
// Draw grid
for (int i = grid_height; i >= 0; --i) {
std::string row = std::to_string(i - center_y) + " | ";
for (int j = 0; j <= grid_width; ++j) {
bool has_point = false;
for (const auto& vec : adjusted_vectors) {
if (vec.first == j && vec.second == i) {
has_point = true;
break;
}
}
row += has_point ? "● " : ". ";
}
mvwaddstr(stdscr, max_y - i, 0, row.substr(0, max_terminal_x - 1).c_str());
}
// Print X-axis labels
std::string x_labels = " ";
for (int j = 0; j <= max_x; ++j) {
x_labels += std::to_string(j - center_x) + " ";
}
mvwaddstr(stdscr, max_y + 1, 0, x_labels.substr(0, max_terminal_x - 1).c_str());
wrefresh(stdscr);
}
#endif

22
src/calc.hpp
View File

@ -1,22 +0,0 @@
#pragma once
#include "units.hpp"
#include <vector>
#include <string>
#include <chrono>
// Calculate distances between all bodies
std::vector<std::vector<Decimal>> calculate_distances(const std::vector<Position>& positions);
// Format a number to a specified number of significant figures
std::string format_sig_figs(Decimal value, int sig_figs);
// Print progress bar
void print_progress_bar(int iteration, int total, std::chrono::time_point<std::chrono::steady_clock> start_time, int length, Decimal step_size);
// Terminal plotting functions (if needed)
#ifdef NCURSES_ENABLED
#include <ncurses.h>
void plot_points_terminal(const std::vector<Position>& vectors, WINDOW* stdscr,
Decimal scale = 500000, int grid_width = 30, int grid_height = 30);
#endif

19
src/config.rs Normal file
View File

@ -0,0 +1,19 @@
use crate::types;
use serde::{Deserialize, Serialize};
#[derive(Debug, Deserialize, Serialize)]
pub struct Body {
pub name: String,
pub mass: types::Mass,
pub position: types::Position,
pub velocity: types::Velocity,
#[serde(default)]
pub acceleration: types::Acceleration,
}
#[derive(Debug, Deserialize)]
pub struct ConfigFile {
pub bodies: Vec<Body>,
}

167
src/main.cpp
View File

@ -1,167 +0,0 @@
#include <iostream>
#include <fstream>
#include <string>
#include <vector>
#include <boost/program_options.hpp>
#include <nlohmann/json.hpp>
#include "simulator.hpp"
#include "body.hpp"
#include "units.hpp"
using json = nlohmann::json;
namespace po = boost::program_options;
struct SimulationConfig {
std::string config_file;
std::string output_file;
int steps;
int steps_per_save;
Decimal step_size; // Changed to Decimal for normalized time
bool overwrite_output;
double simulation_time; // in seconds (real time)
};
// Convert time string to seconds
double parse_time(const std::string& time_str) {
std::string value_str = time_str;
std::string unit;
// Extract the unit (last character)
if (!time_str.empty()) {
unit = time_str.back();
value_str = time_str.substr(0, time_str.length() - 1);
}
double value = std::stod(value_str);
// Convert to seconds based on unit
switch (unit[0]) {
case 's': return value; // seconds
case 'm': return value * 60; // minutes
case 'h': return value * 3600; // hours
case 'd': return value * 86400; // days
default: throw std::runtime_error("Invalid time unit. Use s/m/h/d for seconds/minutes/hours/days");
}
}
SimulationConfig parse_command_line(int argc, char* argv[]) {
SimulationConfig config;
double temp_step_size; // Temporary variable for parsing
po::options_description desc("Orbital Simulator Options");
desc.add_options()
("help,h", "Show help message")
("config,c", po::value<std::string>(&config.config_file)->required(),
"Path to body configuration file (JSON)")
("output,o", po::value<std::string>(&config.output_file)->required(),
"Path to output file")
("time,t", po::value<std::string>()->required(),
"Simulation time with unit (e.g., 1h for 1 hour, 30m for 30 minutes, 2d for 2 days)")
("step-size,s", po::value<double>(&temp_step_size)->default_value(1.0),
"Simulation step size in seconds")
("steps-per-save,p", po::value<int>(&config.steps_per_save)->default_value(100),
"Number of steps between saves")
("overwrite,w", po::bool_switch(&config.overwrite_output),
"Overwrite output file if it exists");
po::variables_map vm;
try {
po::store(po::parse_command_line(argc, argv, desc), vm);
if (vm.count("help")) {
std::cout << desc << "\n";
exit(0);
}
po::notify(vm);
// Parse simulation time
config.simulation_time = parse_time(vm["time"].as<std::string>());
// Convert step size to Decimal and normalize
config.step_size = norm_time(Decimal(temp_step_size));
// Calculate number of steps based on normalized time and step size
config.steps = static_cast<int>(norm_time(config.simulation_time) / config.step_size);
} catch (const po::error& e) {
std::cerr << "Error: " << e.what() << "\n";
std::cerr << desc << "\n";
exit(1);
} catch (const std::exception& e) {
std::cerr << "Error: " << e.what() << "\n";
std::cerr << desc << "\n";
exit(1);
}
return config;
}
std::vector<Body> load_bodies(const std::string& config_file) {
std::ifstream f(config_file);
if (!f.is_open()) {
throw std::runtime_error("Could not open config file: " + config_file);
}
json j;
f >> j;
std::vector<Body> bodies;
for (const auto& body : j["bodies"]) {
std::string name = body["name"];
double mass = body["mass"];
std::vector<double> pos = body["position"];
std::vector<double> vel = body["velocity"];
if (pos.size() != 3 || vel.size() != 3) {
throw std::runtime_error("Position and velocity must be 3D vectors");
}
// Normalize units before creating the body
Position position{norm_pos(pos[0]), norm_pos(pos[1]), norm_pos(pos[2])};
Velocity velocity{norm_vel(vel[0]), norm_vel(vel[1]), norm_vel(vel[2])};
Mass normalized_mass = norm_mass(mass);
bodies.emplace_back(position, velocity, normalized_mass, name);
std::cout << "Loaded " << name << " with mass " << mass << " kg\n";
}
return bodies;
}
int main(int argc, char* argv[]) {
try {
// Parse command line options
auto config = parse_command_line(argc, argv);
// Load bodies from config file
auto bodies = load_bodies(config.config_file);
// Create and run simulator
Simulator simulator(
bodies,
config.step_size,
config.steps_per_save,
config.output_file,
0, // current_step
config.overwrite_output
);
std::cout << "Starting simulation with " << bodies.size() << " bodies\n";
std::cout << "Step size: " << real_time(config.step_size) << " seconds\n";
std::cout << "Simulation time: " << config.simulation_time << " seconds\n";
std::cout << "Total steps: " << config.steps << "\n";
std::cout << "Steps per save: " << config.steps_per_save << "\n";
simulator.run(config.steps);
std::cout << "Simulation completed successfully\n";
return 0;
} catch (const std::exception& e) {
std::cerr << "Error: " << e.what() << std::endl;
return 1;
}
}

122
src/main.rs Normal file
View File

@ -0,0 +1,122 @@
// Standard library
use std::error::Error;
use std::fs::File;
use std::io::BufReader;
use std::path::Path;
use std::time::{Duration,Instant};
// External crates
use clap::Parser;
use log::{info, debug};
use indicatif::{ProgressBar, ProgressStyle};
use humantime;
// Internal modules
mod types;
mod config;
mod simulator;
// Specific uses from modules
use crate::simulator::Simulation;
use crate::types::{norm_time, real_body};
#[derive(Parser, Debug)]
#[command(
version,
about="Orbital mechanics simulator",
long_about = "Given initial conditions you provide to --config, \
this program will numerically integrate and determinate their \
paths based off Newton's law of gravity.")]
struct Args {
///Config file for initial conditions
#[arg(short, long)]
config: String,
/// Time to run simulation for (e.g. 10s, 5m, 2h, 100d)
#[arg(short, long, value_parser = humantime::parse_duration)]
time: Duration,
///Step size for simulation (seconds)
#[arg(short, long, default_value_t = 10.0)]
step_size: f64,
///How often to update progress bar and save (seconds)
#[arg(short = 'P', long, default_value_t = 1000)]
steps_per_save: usize,
/// Filename to save trajectory to
#[arg(short, long)]
output_file: String,
}
fn read_config<P: AsRef<Path>>(path: P) -> Result<config::ConfigFile, Box<dyn Error>> {
let file = File::open(path)?;
let reader = BufReader::new(file);
let u = serde_json::from_reader(reader)?;
Ok(u)
}
//fn parse_time(arg: &str)
fn format_duration_single_unit(dur: Duration) -> String {
let secs = dur.as_secs_f64();
const MINUTE: f64 = 60.0;
const HOUR: f64 = 60.0 * MINUTE;
const DAY: f64 = 24.0 * HOUR;
const YEAR: f64 = 365.25 * DAY;
if secs >= YEAR {
format!("{:.0} years", (secs / YEAR).round())
} else if secs >= DAY {
format!("{:.0} days", (secs / DAY).round())
} else if secs >= HOUR {
format!("{:.0} hours", (secs / HOUR).round())
} else if secs >= MINUTE {
format!("{:.0} minutes", (secs / MINUTE).round())
} else {
format!("{:.0} seconds", secs.round())
}
}
fn main() {
env_logger::init();
let args = Args::parse();
info!("Loading initial parameters from {}", args.config);
let conf = read_config(args.config).unwrap();
for body in &conf.bodies {
info!("Loaded {} with mass {:.3e} kg", body.name, body.mass);
debug!("R_i = {:?}, V_i = {:?}", body.position, body.velocity);
}
let n_steps = (args.time.as_secs() as f64 / args.step_size) as usize;
let pb = ProgressBar::new(n_steps.try_into().unwrap());
pb.set_style(
ProgressStyle::with_template("[{elapsed_precise}] {bar:40.cyan/blue} {percent_precise}% \n\
Time remaining: {eta} \n\
Current simulation speed: {msg}")
.unwrap()
.progress_chars("=>-"),
);
let mut sim = Simulation::new(
conf.bodies,
norm_time(args.step_size),
args.steps_per_save,
args.output_file,
);
let start = Instant::now();
sim.run(n_steps, Some(|| {
let elapsed = start.elapsed().as_secs() as f64 + 1.0;
let speed = Duration::from_secs_f64(pb.position() as f64 * args.step_size / elapsed);
pb.set_message(format!("{} /sec", format_duration_single_unit(speed)));
pb.inc(args.steps_per_save as u64);
})
);
}

121
src/simulator.cpp
View File

@ -1,121 +0,0 @@
#include "simulator.hpp"
#include "calc.hpp"
#include <fstream>
#include <chrono>
#include <iostream>
#include <stdexcept>
Simulator::Simulator(const std::vector<Body>& bodies,
Decimal step_size,
int steps_per_save,
const std::filesystem::path& output_file,
int current_step,
bool overwrite_output)
: bodies(bodies),
step_size(step_size),
steps_per_save(steps_per_save),
output_file(output_file),
current_step(current_step) {
if (std::filesystem::exists(output_file) && !overwrite_output) {
throw std::runtime_error("File " + output_file.string() + " exists and overwrite flag not given.");
}
if (std::filesystem::exists(output_file) && overwrite_output) {
std::cout << "Warning! Overwriting file: " << output_file.string() << std::endl;
// Clear the file if we're overwriting
std::ofstream clear(output_file, std::ios::trunc);
clear.close();
}
out.open(output_file, std::ios::app);
if (!out) {
throw std::runtime_error("Failed to open output file: " + output_file.string());
}
for (const auto& body : bodies) {
out << body.getName() << ": mass=" << body.getMass();
out << "\n";
}
out << "\n";
// Write initial state
checkpoint();
}
Simulator Simulator::from_checkpoint(const std::filesystem::path& output_file) {
// TODO: Implement checkpoint loading
// This would require implementing a binary format for saving/loading checkpoints
throw std::runtime_error("Checkpoint loading not implemented yet");
}
void Simulator::run(int steps) {
auto start_time = std::chrono::steady_clock::now();
for (int i = 0; i < steps; ++i) {
calculate_forces();
move_bodies();
if (i % steps_per_save == 0) {
checkpoint();
print_progress_bar(i + 1, steps, start_time, 50, step_size);
}
}
}
void Simulator::calculate_forces() {
std::vector<Position> positions;
positions.reserve(bodies.size());
for (const auto& body : bodies) {
positions.push_back(body.getPosition());
}
auto dists = calculate_distances(positions);
// Reset all accelerations to zero
for (auto& body : bodies) {
body.setAcceleration(Acceleration{Decimal(0), Decimal(0), Decimal(0)});
}
for (size_t i = 0; i < bodies.size(); i++) {
for (size_t j = i + 1; j < bodies.size(); j++) {
Position vec;
for (int k = 0; k < 3; ++k) {
vec[k] = positions[i][k] - positions[j][k];
}
Decimal dist = std::sqrt(vec[0] * vec[0] + vec[1] * vec[1] + vec[2] * vec[2]);
// Calculate force magnitude using Newton's law of gravitation
// F = G * m1 * m2 / r^2 BUT G = 1, and we'll multiply by the opposite mass later
// for the acceleration. Use r^3 to avoid normalizing vec when multiplying later
Decimal force_magnitude = 1 / (dist * dist * dist);
Decimal acc_magnitude_i = force_magnitude * bodies[j].getMass();
Decimal acc_magnitude_j = force_magnitude * bodies[i].getMass();
// Convert to vector form
Acceleration acc_i, acc_j;
for (int k = 0; k < 3; ++k) {
acc_i[k] = -vec[k] * acc_magnitude_i;
acc_j[k] = vec[k] * acc_magnitude_j;
}
bodies[i].addAcceleration(acc_i);
bodies[j].addAcceleration(acc_j);
}
}
}
void Simulator::move_bodies() {
for (auto& body : bodies) {
body.step(step_size);
}
}
void Simulator::checkpoint() {
for (const auto& body : bodies) {
out << body.toString() << "\n";
}
out.flush();
}

43
src/simulator.hpp
View File

@ -1,43 +0,0 @@
#pragma once
#include "body.hpp"
#include <vector>
#include <string>
#include <filesystem>
#include <memory>
#include <fstream>
class Simulator {
public:
Simulator(const std::vector<Body>& bodies,
Decimal step_size,
int steps_per_save,
const std::filesystem::path& output_file,
int current_step = 0,
bool overwrite_output = false);
// Create simulator from checkpoint
static Simulator from_checkpoint(const std::filesystem::path& output_file);
// Run simulation
void run(int steps);
// Getters
const std::vector<Body>& getBodies() const { return bodies; }
Decimal getStepSize() const { return step_size; }
int getStepsPerSave() const { return steps_per_save; }
const std::filesystem::path& getOutputFile() const { return output_file; }
int getCurrentStep() const { return current_step; }
private:
void calculate_forces();
void move_bodies();
void checkpoint();
std::vector<Body> bodies;
Decimal step_size;
int steps_per_save;
std::filesystem::path output_file;
std::ofstream out;
int current_step;
};

113
src/simulator.rs Normal file
View File

@ -0,0 +1,113 @@
use std::fs::OpenOptions;
use std::io::BufWriter;
use serde::Serialize;
use log::{debug, trace};
use glam::DVec3;
use crate::config::Body;
use crate::types::{norm_mass, norm_pos, norm_vel, norm_time, real_pos, real_vel, real_time, real_body};
pub struct Simulation {
pub bodies: Vec<Body>,
step_size: f64,
steps_per_save: usize,
save_file: String
}
#[derive(Serialize)]
struct Snapshot<'a> {
time: f64,
bodies: &'a [Body],
}
impl Simulation {
pub fn new(
mut bodies: Vec<Body>,
mut step_size: f64,
steps_per_save: usize,
save_file: String,
) -> Self {
let n = bodies.len();
for i in 0..n {
bodies[i].mass = norm_mass(bodies[i].mass);
bodies[i].position = norm_pos(bodies[i].position);
bodies[i].velocity = norm_vel(bodies[i].velocity);
}
step_size = norm_time(step_size);
Self {bodies, step_size, steps_per_save, save_file}
}
pub fn run<F>(&mut self, steps: usize, mut on_step: Option<F>)
where F: FnMut() {
let file = OpenOptions::new()
.create(true)
.append(true)
.open(&self.save_file);
let mut writer = BufWriter::new(file.unwrap());
for i in 0..steps {
debug!("Step: {}", i);
self.reset_accelerations();
self.caclulate_accelerations();
self.step_bodies();
if i % self.steps_per_save == 0 {
//save the state
let real_bodies: Vec<Body> = self.bodies.iter().map(real_body).collect();
let snapshot = Snapshot {
time: real_time(i as f64*self.step_size),
bodies: &real_bodies,
};
bincode::serialize_into(&mut writer, &snapshot).expect("Couldn't write to trajectory. ");
//Do the progress bar
if let Some(f) = &mut on_step {
f();
}
}
}
}
fn caclulate_accelerations(&mut self) {
let r_hat_over_r3 = self.get_rhat_over_r_three();
let n = self.bodies.len();
for i in 0..(n-1) {
let mass_i = self.bodies[i].mass;
for j in (i+1)..n {
let mass_j = self.bodies[j].mass;
self.bodies[i].acceleration += r_hat_over_r3[i][j]*mass_j;
self.bodies[j].acceleration -= r_hat_over_r3[i][j]*mass_i;
}
}
}
fn reset_accelerations(&mut self) {
for i in 0..self.bodies.len() {
self.bodies[i].acceleration = DVec3::ZERO;
}
}
fn get_rhat_over_r_three (&self) -> Vec<Vec<DVec3>>{
let n = self.bodies.len();
let mut r_hat_over_r3 = vec![vec![DVec3::ZERO; n]; n];
for i in 0..(n-1) {
for j in (i+1)..n {
let r_ij = self.bodies[j].position - self.bodies[i].position;
let dist = r_ij.length();
r_hat_over_r3[i][j] = r_ij / dist.powf(3.0);
}
}
trace!("rhat over r3: {:?}", r_hat_over_r3);
return r_hat_over_r3;
}
fn step_bodies(&mut self) {
for body in &mut self.bodies {
//do for each of three (x,y,z) dimensions
body.position += self.step_size*body.velocity;
body.velocity += self.step_size*body.acceleration;
trace!("{} now at {:?}", body.name, real_pos(body.position));
trace!("{} moving at {:?}", body.name, real_vel(body.velocity));
}
}
}

105
src/types.rs Normal file
View File

@ -0,0 +1,105 @@
#![allow(unused)]
use glam::DVec3;
use once_cell::sync::Lazy;
use crate::config::Body;
pub type Position = DVec3;
pub type Velocity = DVec3;
pub type Acceleration = DVec3;
pub type Mass = f64;
pub type Time = f64;
// Constants
const EARTH_RADIUS: f64 = 6.378e6; //meters
const EARTH_MASS: f64 = 5.972e24; //kg
const EARTH_ORBITAL_VELOCITY: f64 = 2.9780e4; //m/s
const AU: f64 = 1.49597870700e11; //meters
const MOON_MASS: Mass = 7.34767309e22; // kg
const MOON_ORBITAL_VELOCITY: f64 = 1.022e3; //m/s relative to earth
const SUN_MASS: f64 = 1.989e30; //kg
const SUN_RADIUS: f64 = 6.957e8; //meters
const G: f64 = 6.67430e-11;
const R_0: f64 = EARTH_RADIUS;
const M_0: f64 = EARTH_MASS;
static T_0: Lazy<f64> = Lazy::new(|| {
(R_0.powf(3.0) / (G * M_0)).sqrt()
});
#[inline]
pub fn norm_pos(pos: Position) -> Position {
pos / R_0
}
#[inline]
pub fn real_pos(pos: Position) -> Position {
pos * R_0
}
#[inline]
pub fn norm_mass(mass: Mass) -> Mass {
mass / M_0
}
#[inline]
pub fn real_mass(mass: Mass) -> Mass {
mass * M_0
}
#[inline]
pub fn norm_time(time: Time) -> Time {
time / *T_0
}
#[inline]
pub fn real_time(time: Time) -> Time {
time * *T_0
}
#[inline]
pub fn norm_vel(vel: Velocity) -> Velocity {
vel / (R_0 / *T_0)
}
#[inline]
pub fn real_vel(vel: Velocity) -> Velocity {
vel * (R_0 / *T_0)
}
#[inline]
pub fn norm_acc(acc: Acceleration) -> Acceleration {
acc / (R_0 / (*T_0 * *T_0))
}
#[inline]
pub fn real_acc(acc: Acceleration) -> Acceleration {
acc * (R_0 / (*T_0 * *T_0))
}
#[inline]
pub fn norm_body(body: Body) -> Body {
Body {
name: body.name,
mass: norm_mass(body.mass),
position: norm_pos(body.position),
velocity: norm_vel(body.velocity),
acceleration: DVec3::ZERO,
}
}
#[inline]
pub fn real_body(body: &Body) -> Body {
Body {
name: body.name.clone(),
mass: real_mass(body.mass),
position: real_pos(body.position),
velocity: real_vel(body.velocity),
acceleration: DVec3::ZERO,
}
}

46
src/units.hpp
View File

@ -1,46 +0,0 @@
#pragma once
#include <array>
#include <string>
#include <cmath>
//#include <boost/multiprecision/cpp_dec_float.hpp>
using Decimal = long double; //boost::multiprecision::cpp_dec_float_50;
// Type aliases for clarity
using Position = std::array<Decimal, 3>;
using Velocity = std::array<Decimal, 3>;
using Acceleration = std::array<Decimal, 3>;
using Mass = Decimal;
// Constants
const Decimal EARTH_MASS = 5972e21;//Decimal("5972e21"); // kg
const Decimal EARTH_RADIUS = 6378e3;//Decimal("6378e3"); // meters
const Decimal EARTH_ORBITAL_VELOCITY = 29780;//Decimal("29780"); // m/s
const Decimal AU = 149597870700;//Decimal("149597870700"); // meters
const Decimal MOON_MASS = 734767309e14;//Decimal("734767309e14");
const Decimal MOON_ORBITAL_VELOCITY = 1022;//Decimal("1022"); // m/s relative to earth
const Decimal SUN_MASS = 1989e27;//Decimal("1989e27"); // kg
const Decimal SUN_RADIUS = 6957e5;//Decimal("6957e5"); // meters
const Decimal PI = 3.14159265358979323846264338327950288419716939937510;
// Normalizing constants
const Decimal G = 6.67430e-11;
const Decimal r_0 = EARTH_RADIUS;
const Decimal m_0 = 5.972e24;
const Decimal t_0 = std::sqrt((r_0 * r_0 * r_0) / (G * m_0));
// Utility functions
inline Decimal norm_pos(Decimal pos) { return pos / r_0; }
inline Decimal real_pos(Decimal pos) { return pos * r_0; }
inline Decimal norm_mass(Decimal mass) { return mass / m_0; }
inline Decimal real_mass(Decimal mass) { return mass * m_0; }
inline Decimal norm_time(Decimal time) { return time / t_0; }
inline Decimal real_time(Decimal time) { return time * t_0; }
inline Decimal norm_vel(Decimal vel) { return vel / (r_0/t_0); }
inline Decimal real_vel(Decimal vel) { return vel * (r_0/t_0); }
inline Decimal norm_acc(Decimal acc) { return acc / (r_0/(t_0*t_0)); }
inline Decimal real_acc(Decimal acc) { return acc * (r_0/(t_0*t_0)); }

44
test.py
View File

@ -1,44 +0,0 @@
from orbiter.orbits.body import Body
from orbiter.orbits.simulator import Simulator
from orbiter.units import *
from pathlib import Path
from decimal import Decimal, getcontext
getcontext().prec = 50
#set up the earth
earth = Body(
Position([0,0,0]),
Velocity([0,0,0]),
Mass(norm_mass(EARTH_MASS)),
"Earth"
)
r = EARTH_RADIUS+100_000
#Lets try a body just outside earth accelerating in. Should be 9.8m/s2
person = Body(
Position([norm_pos(r),0,0]), #10_000m in the sky, airliner height!
Velocity([0,(Decimal(0.5)/norm_pos(r)).sqrt(),0]), #orbital velocity
Mass(norm_mass(80)), #avg person
"Person"
)
T = 2*pi_approx*norm_pos(r)/person.V[1]
time_to_run = T*3 #norm_time(2000)
STEP_SIZE = Decimal(6e-4)
n_steps = int(time_to_run/STEP_SIZE)
def main():
print("Before: ")
print(str(person))
print(str(earth))
import cProfile
s = Simulator([earth,person], STEP_SIZE, 100, Path("hello_world"))
cProfile.run(s.run(n_steps))
print("\nAfter:")
print(str(person))
print(str(earth))
main()

111
tests/body_test.cpp
View File

@ -1,111 +0,0 @@
#include <gtest/gtest.h>
#include "body.hpp"
#include <cmath>
#include <memory>
class BodyTest : public testing::Test {
protected:
BodyTest() {
test_body = std::make_unique<Body>(
Position{Decimal(0), Decimal(0), Decimal(0)},
Velocity{Decimal(0), Decimal(0), Decimal(0)},
Mass(1.0),
"test_body"
);
}
std::unique_ptr<Body> test_body;
};
TEST_F(BodyTest, AddAcceleration) {
Acceleration new_A{Decimal(1.0), Decimal(2.0), Decimal(3.0)};
test_body->addAcceleration(new_A);
const auto& A = test_body->getAcceleration();
EXPECT_DOUBLE_EQ(A[0], 1.0);
EXPECT_DOUBLE_EQ(A[1], 2.0);
EXPECT_DOUBLE_EQ(A[2], 3.0);
// Add another acceleration
Acceleration another_A{Decimal(2.0), Decimal(3.0), Decimal(4.0)};
test_body->addAcceleration(another_A);
EXPECT_DOUBLE_EQ(A[0], 3.0);
EXPECT_DOUBLE_EQ(A[1], 5.0);
EXPECT_DOUBLE_EQ(A[2], 7.0);
}
TEST_F(BodyTest, Step) {
// Set initial velocity and acceleration
test_body->setAcceleration(Acceleration{Decimal(1.0), Decimal(2.0), Decimal(3.0)});
// Take a step
test_body->step(1.0);
// Check new position
const auto& X = test_body->getPosition();
EXPECT_DOUBLE_EQ(X[0], 0.0);
EXPECT_DOUBLE_EQ(X[1], 0.0);
EXPECT_DOUBLE_EQ(X[2], 0.0);
// Check new velocity
const auto& V = test_body->getVelocity();
EXPECT_DOUBLE_EQ(V[0], 1.0);
EXPECT_DOUBLE_EQ(V[1], 2.0);
EXPECT_DOUBLE_EQ(V[2], 3.0);
// Check acceleration is reset
const auto& A = test_body->getAcceleration();
EXPECT_DOUBLE_EQ(A[0], 0.0);
EXPECT_DOUBLE_EQ(A[1], 0.0);
EXPECT_DOUBLE_EQ(A[2], 0.0);
}
TEST_F(BodyTest, Energy) {
// Set position and velocity through save/load
auto state = std::make_tuple(
Position{Decimal(1.0), Decimal(0.0), Decimal(0.0)},
Velocity{Decimal(1.0), Decimal(0.0), Decimal(0.0)},
Mass(1.0)
);
test_body = std::make_unique<Body>(Body::load(state));
// Calculate expected values
Decimal expected_ke = Decimal(0.5); // 0.5 * m * v^2
Decimal expected_pe = Decimal(-1.0); // -m/r
Decimal expected_total = expected_ke + expected_pe;
EXPECT_DOUBLE_EQ(test_body->ke(), expected_ke);
EXPECT_DOUBLE_EQ(test_body->pe(), expected_pe);
EXPECT_DOUBLE_EQ(test_body->E(), expected_total);
}
TEST_F(BodyTest, SaveAndLoad) {
// Set some values through save/load
auto state = std::make_tuple(
Position{Decimal(1.0), Decimal(2.0), Decimal(3.0)},
Velocity{Decimal(4.0), Decimal(5.0), Decimal(6.0)},
Mass(7.0)
);
test_body = std::make_unique<Body>(Body::load(state));
// Save state
auto saved_state = test_body->save();
// Create new body from saved state
Body loaded_body = Body::load(saved_state);
// Verify loaded values
const auto& X = loaded_body.getPosition();
const auto& V = loaded_body.getVelocity();
const auto& m = loaded_body.getMass();
EXPECT_DOUBLE_EQ(X[0], 1.0);
EXPECT_DOUBLE_EQ(X[1], 2.0);
EXPECT_DOUBLE_EQ(X[2], 3.0);
EXPECT_DOUBLE_EQ(V[0], 4.0);
EXPECT_DOUBLE_EQ(V[1], 5.0);
EXPECT_DOUBLE_EQ(V[2], 6.0);
EXPECT_DOUBLE_EQ(m, 7.0);
}

10
tests/calc_test.cpp
View File

@ -1,10 +0,0 @@
#include <gtest/gtest.h>
#include "calc.hpp"
#include <cmath>
TEST(CalcTest, FormatSigFigs) {
// Test positive numbers
EXPECT_EQ(format_sig_figs(123.456, 3), "1.23e+02");
EXPECT_EQ(format_sig_figs(123.456, 4), "1.235e+02");
EXPECT_EQ(format_sig_figs(123.456, 5), "1.2346e+02");
}

54
tests/simulator_test.cpp
View File

@ -1,54 +0,0 @@
// #include <gtest/gtest.h>
// #include "simulator.hpp"
// #include <vector>
// #include <filesystem>
// #include <memory>
// class SimulatorTest : public testing::Test {
// protected:
// SimulatorTest() :
// bodies({
// Body(
// Position{Decimal(0), Decimal(0), Decimal(0)},
// Velocity{Decimal(0), Decimal(0), Decimal(0)},
// Mass(1.0),
// "body1"
// ),
// Body(
// Position{Decimal(1), Decimal(0), Decimal(0)},
// Velocity{Decimal(0), Decimal(1), Decimal(0)},
// Mass(1.0),
// "body2"
// )
// })
// {
// simulator = std::make_unique<Simulator>(
// bodies,
// Decimal(0.1), // step_size
// 1, // steps_per_save
// std::filesystem::path("test_output.json"), // output_file
// 0, // current_step
// true // overwrite_output
// );
// }
// std::vector<Body> bodies;
// std::unique_ptr<Simulator> simulator;
// };
// TEST_F(SimulatorTest, Step) {
// // Take a step
// //TODO
// }
// TEST_F(SimulatorTest, TotalEnergy) {
// //TODO
// // Decimal initial_energy = simulator->total_energy();
// // simulator->step(Decimal(0.1));
// // Decimal new_energy = simulator->total_energy();
// // EXPECT_NEAR(initial_energy, new_energy, 1e-10);
// }

BIN
tracjtory.out Normal file
View File

Binary file not shown.

BIN
tracjtory.out2 Normal file
View File

Binary file not shown.