280 lines
9.3 KiB
Python
280 lines
9.3 KiB
Python
"""
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三体问题配置管理模块
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"""
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import numpy as np
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from typing import List, Dict, Any, Optional
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from .particle import Particle
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class ThreeBodyConfig:
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"""三体问题配置类"""
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@staticmethod
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def create_figure8_config() -> List[Particle]:
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"""
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创建8字形轨道配置（著名的稳定三体轨道）
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返回:
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三个质点的列表
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"""
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# 8字形轨道的初始条件（等质量）
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m = 1.0 # 质量
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# 位置 (Chenciner & Montgomery, 2000)
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r1 = np.array([0.97000436, -0.24308753, 0.0])
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r2 = np.array([-0.97000436, 0.24308753, 0.0])
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r3 = np.array([0.0, 0.0, 0.0])
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# 速度
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v1 = np.array([0.466203685, 0.43236573, 0.0])
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v2 = np.array([0.466203685, 0.43236573, 0.0])
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v3 = np.array([-0.93240737, -0.86473146, 0.0])
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particles = [
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Particle(mass=m, position=r1, velocity=v1, name="Star A", color="red"),
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Particle(mass=m, position=r2, velocity=v2, name="Star B", color="green"),
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Particle(mass=m, position=r3, velocity=v3, name="Star C", color="blue")
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]
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return particles
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@staticmethod
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def create_lagrange_point_config(lagrange_point: int = 4) -> List[Particle]:
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"""
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创建拉格朗日点配置
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参数:
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lagrange_point: 拉格朗日点编号 (4=L4, 5=L5)
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返回:
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三个质点的列表
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"""
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if lagrange_point not in [4, 5]:
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raise ValueError("lagrange_point 必须是 4 (L4) 或 5 (L5)")
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# 大质量天体（类似太阳）
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m_sun = 1.0
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# 小质量天体（类似地球）
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m_earth = 3e-6 # 地球质量/太阳质量
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# 测试质点（类似小行星）
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m_test = 1e-8
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# 大质量天体在原点
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r_sun = np.array([0.0, 0.0, 0.0])
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v_sun = np.array([0.0, 0.0, 0.0])
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# 小质量天体在圆形轨道上（1 AU距离）
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r_earth = np.array([1.0, 0.0, 0.0])
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# 圆形轨道速度：v = sqrt(G*M/r)
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v_earth = np.array([0.0, 2*np.pi, 0.0]) # 2π AU/年
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# 拉格朗日点位置（等边三角形）
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if lagrange_point == 4: # L4
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r_test = np.array([0.5, np.sqrt(3)/2, 0.0])
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else: # L5
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r_test = np.array([0.5, -np.sqrt(3)/2, 0.0])
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# 测试质点的速度（与地球相同角速度）
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v_test = np.array([-np.sqrt(3)/2 * 2*np.pi, 0.5 * 2*np.pi, 0.0])
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particles = [
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Particle(mass=m_sun, position=r_sun, velocity=v_sun, name="Sun", color="yellow"),
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Particle(mass=m_earth, position=r_earth, velocity=v_earth, name="Earth", color="blue"),
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Particle(mass=m_test, position=r_test, velocity=v_test, name="Test", color="gray")
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]
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return particles
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@staticmethod
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def create_random_config(masses: Optional[List[float]] = None,
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position_range: float = 2.0,
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velocity_scale: float = 1.0) -> List[Particle]:
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"""
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创建随机初始条件配置
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参数:
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masses: 质量列表（如果为None则使用随机质量）
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position_range: 位置范围（±position_range）
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velocity_scale: 速度缩放因子
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返回:
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三个质点的列表
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"""
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if masses is None:
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# 随机质量（在0.5到2.0之间）
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masses = np.random.uniform(0.5, 2.0, 3)
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if len(masses) != 3:
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raise ValueError("需要恰好3个质量值")
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particles = []
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colors = ['red', 'green', 'blue']
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names = ['Star A', 'Star B', 'Star C']
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for i in range(3):
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# 随机位置
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position = np.random.uniform(-position_range, position_range, 3)
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# 随机速度（确保系统总动量接近零）
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velocity = np.random.uniform(-velocity_scale, velocity_scale, 3)
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particles.append(
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Particle(mass=masses[i], position=position, velocity=velocity,
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name=names[i], color=colors[i])
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)
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# 调整速度使系统总动量接近零
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total_momentum = sum(p.mass * p.velocity for p in particles)
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total_mass = sum(p.mass for p in particles)
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for p in particles:
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p.velocity -= total_momentum / total_mass
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return particles
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@staticmethod
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def create_binary_star_config() -> List[Particle]:
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"""
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创建双星系统+测试质点配置
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返回:
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三个质点的列表
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"""
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# 双星质量
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m1 = 1.0
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m2 = 0.8
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# 双星位置（在椭圆轨道上）
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# 半长轴
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a = 1.0
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# 偏心率
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e = 0.3
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# 质心在原点
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r1 = np.array([-m2/(m1+m2) * a * (1+e), 0.0, 0.0])
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r2 = np.array([m1/(m1+m2) * a * (1+e), 0.0, 0.0])
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# 计算轨道速度（简化圆形轨道近似）
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# 对于椭圆轨道，速度更复杂，这里使用简化
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orbital_speed = np.sqrt(4*np.pi**2 * (m1+m2) / (2*a))
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v1 = np.array([0.0, orbital_speed * m2/(m1+m2), 0.0])
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v2 = np.array([0.0, -orbital_speed * m1/(m1+m2), 0.0])
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# 测试质点（小质量）
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m_test = 0.01
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r_test = np.array([0.0, 2.0, 0.0])
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v_test = np.array([0.5, 0.0, 0.0])
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particles = [
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Particle(mass=m1, position=r1, velocity=v1, name="Primary", color="red"),
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Particle(mass=m2, position=r2, velocity=v2, name="Secondary", color="green"),
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Particle(mass=m_test, position=r_test, velocity=v_test, name="Test", color="blue")
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]
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return particles
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@staticmethod
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def create_custom_config(config_dict: Dict[str, Any]) -> List[Particle]:
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"""
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从字典创建自定义配置
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参数:
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config_dict: 包含配置信息的字典
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返回:
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三个质点的列表
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"""
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particles = []
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for i in range(3):
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key = f"particle_{i+1}"
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if key not in config_dict:
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raise ValueError(f"配置中缺少 {key}")
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p_config = config_dict[key]
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particle = Particle(
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mass=p_config.get('mass', 1.0),
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position=np.array(p_config.get('position', [0.0, 0.0, 0.0])),
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velocity=np.array(p_config.get('velocity', [0.0, 0.0, 0.0])),
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name=p_config.get('name', f"Particle {i+1}"),
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color=p_config.get('color', None)
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)
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particles.append(particle)
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return particles
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@staticmethod
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def save_config(particles: List[Particle], filename: str):
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"""
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保存配置到文件
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参数:
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particles: 质点列表
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filename: 文件名
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"""
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config_dict = {}
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for i, p in enumerate(particles):
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config_dict[f"particle_{i+1}"] = {
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'mass': float(p.mass),
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'position': p.position.tolist(),
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'velocity': p.velocity.tolist(),
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'name': p.name,
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'color': p.color
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}
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import json
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with open(filename, 'w') as f:
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json.dump(config_dict, f, indent=2)
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print(f"配置已保存到: {filename}")
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@staticmethod
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def load_config(filename: str) -> List[Particle]:
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"""
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从文件加载配置
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参数:
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filename: 文件名
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返回:
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三个质点的列表
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"""
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import json
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with open(filename, 'r') as f:
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config_dict = json.load(f)
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return ThreeBodyConfig.create_custom_config(config_dict)
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@staticmethod
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def print_config_summary(particles: List[Particle]):
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"""打印配置摘要"""
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print("=" * 60)
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print("三体问题配置摘要")
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print("=" * 60)
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total_mass = 0.0
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total_momentum = np.zeros(3)
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total_angular_momentum = np.zeros(3)
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for i, p in enumerate(particles):
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print(f"\n质点 {i+1} ({p.name}):")
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print(f" 质量: {p.mass:.6f} M_sun")
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print(f" 位置: [{p.position[0]:.6f}, {p.position[1]:.6f}, {p.position[2]:.6f}] AU")
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print(f" 速度: [{p.velocity[0]:.6f}, {p.velocity[1]:.6f}, {p.velocity[2]:.6f}] AU/yr")
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total_mass += p.mass
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total_momentum += p.mass * p.velocity
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angular_momentum = np.cross(p.position, p.mass * p.velocity)
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total_angular_momentum += angular_momentum
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print("\n" + "=" * 60)
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print("系统总质量: {:.6f} M_sun".format(total_mass))
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print("系统总动量: [{:.6e}, {:.6e}, {:.6e}]".format(
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total_momentum[0], total_momentum[1], total_momentum[2]))
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print("系统总角动量: [{:.6e}, {:.6e}, {:.6e}]".format(
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total_angular_momentum[0], total_angular_momentum[1], total_angular_momentum[2]))
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print("=" * 60) |