File:Field tidal.svg - 维基百科，自由的百科全书

摘要

描述

English: Differential gravity field that causes tides.

日期

2014年5月23日

来源

自己的作品

作者

Krishnavedala

其他版本

македонски

SVG开发

该SVG的源代码为有效代码。

本矢量图使用Matplotlib创作。

The file size of this SVG plot may be irrationally large because its text has been converted to paths inhibiting translations.

源代码

Matplotlib code

import matplotlib.pyplot as plt import numpy as np  if __name__ == "__main__":     fig = plt.figure(figsize=(15.2, 8))     ax = fig.add_subplot(111)      R = 10     p0, q0 = [20, 0], [-20, 0]     k = 275      dist = lambda p1, p2: np.sqrt( (p1[0]-p2[0])**2 + (p1[1]-p2[1])**2 )     force = lambda r: - k / r**2      theta = np.linspace(-np.pi, np.pi, 50)     for t in theta:         p1 = [-R * np.cos(t), R * np.sin(t)]         if t < np.pi * 0.5 and t > -np.pi * 0.5:             r = dist(q0, p1)         else:             r = dist(p0, p1)         F = force(r)         ax.arrow(p1[0], p1[1], F * np.cos(t), F * np.sin(t), head_width=0.5, head_length=0.7, fc='k')      ax.annotate(r"+", xytext=(0,0), size=30, xy=(0,0), ha="center", va="center")     ax.annotate(r"Satellite", xy=(25,0), xytext=(15,0),                 size=30, va="center",                 arrowprops=dict(arrowstyle="fancy", fc='k'))     ax.set_xlim(-13, 25)     ax.set_ylim(-11, 11)     ax.plot(-R * np.cos(theta), R * np.sin(theta), linewidth=3.)     ax.axis('off')     plt.savefig('field tidal.svg', bbox_inches='tight', pad_inches=.15, transparent='true')